title: Head of state

text: In contrast, the only contact the president of Ireland has with the Irish government is through a formal briefing session given by the taoiseach (head of government) to the president. However, the president has no access to documentation and all access to ministers goes through the Department of the Taoiseach. The president does, however, hold limited reserve powers, such as referring a bill to the Supreme Court to test its constitutionality, which are used under the president's discretion.


title: Head of state

text: The most extreme non-executive republican head of state is the president of Israel, which holds no reserve powers whatsoever. The least ceremonial powers held by the president are to provide a mandate to attempt to form a government, to approve the dissolution of the Knesset made by the prime minister, and to pardon criminals or to commute their sentence.


title: Head of state

text: Some parliamentary republics (like South Africa, Botswana and Kiribati) have fused the roles of the head of state with the head of government (like in a presidential system), while having the sole executive officer, often called a president, being dependent on the Parliament's confidence to rule (like in a parliamentary system). While also being the leading symbol of the nation, the president in this system acts mostly as a prime minister since the incumbent must be a member of the legislature at the time of the election, answer question sessions in Parliament, avoid motions of no confidence, etc.


title: Head of state

text: Semi-presidential systems combine features of presidential and parliamentary systems, notably (in the president-parliamentary subtype) a requirement that the government be answerable to both the president and the legislature. The constitution of the Fifth French Republic provides for a prime minister who is chosen by the president, but who nevertheless must be able to gain support in the National Assembly. Should a president be of one side of the political spectrum and the opposition be in control of the legislature, the president is usually obliged to select someone from the opposition to become prime minister, a process known as Cohabitation. President François Mitterrand, a Socialist, for example, was forced to cohabit with the neo-Gaullist (right wing) Jacques Chirac, who became his prime minister from 1986 to 1988. In the French system, in the event of cohabitation, the president is often allowed to set the policy agenda in security and foreign affairs and the prime minister runs the domestic and economic agenda.


title: Head of state

text: Other countries evolve into something akin to a semi-presidential system or indeed a full presidential system. Weimar Germany, for example, in its constitution provided for a popularly elected president with theoretically dominant executive powers that were intended to be exercised only in emergencies, and a cabinet appointed by him from the Reichstag, which was expected, in normal circumstances, to be answerable to the Reichstag. Initially, the president was merely a symbolic figure with the Reichstag dominant; however, persistent political instability, in which governments often lasted only a few months, led to a change in the power structure of the republic, with the president's emergency powers called increasingly into use to prop up governments challenged by critical or even hostile Reichstag votes. By 1932, power had shifted to such an extent that the German president, Paul von Hindenburg, was able to dismiss a chancellor and select his own person for the job, even though the outgoing chancellor possessed the confidence of the Reichstag while the new chancellor did not. Subsequently, President von Hindenburg used his power to appoint Adolf Hitler as Chancellor without consulting the Reichstag.


title: Head of state

text: "Note: The head of state in a "presidential" system may not actually hold the title of "president" - the name of the system refers to any head of state who actually governs and is not directly dependent on the legislature to remain in office."


title: Head of state

text: Some constitutions or fundamental laws provide for a head of state who is not only in theory but in practice chief executive, operating separately from, and independent from, the legislature. This system is known as a "presidential system" and sometimes called the "imperial model", because the executive officials of the government are answerable solely and exclusively to a presiding, acting head of state, and is selected by and on occasion dismissed by the head of state without reference to the legislature. It is notable that some presidential systems, while not providing for collective executive accountability to the legislature, may require legislative approval for individuals prior to their assumption of cabinet office and empower the legislature to remove a president from office (for example, in the United States of America). In this case the debate centers on confirming them into office, not removing them from office, and does not involve the power to reject or approve proposed cabinet members "en bloc", so accountability does not operate in the same sense understood as a parliamentary system.


title: Head of state

text: Presidential systems are a notable feature of constitutions in the Americas, including those of Argentina, Brazil, Colombia, El Salvador, Mexico and Venezuela; this is generally attributed to the strong influence of the United States in the region, and as the United States Constitution served as an inspiration and model for the Latin American wars of independence of the early 19th century. Most presidents in such countries are selected by democratic means (popular direct or indirect election); however, like all other systems, the presidential model also encompasses people who become head of state by other means, notably through military dictatorship or "coup d'état", as often seen in Latin American, Middle Eastern and other presidential regimes. Some of the characteristics of a presidential system, such as a strong dominant political figure with an executive answerable to them, not the legislature can also be found among absolute monarchies, parliamentary monarchies and single party (e.g., Communist) regimes, but in most cases of dictatorship, their stated constitutional models are applied in name only and not in political theory or practice.


title: Head of state

text: In the 1870s in the United States, in the aftermath of the impeachment of President Andrew Johnson and his near-removal from office, it was speculated that the United States, too, would move from a presidential system to a semi-presidential or even parliamentary one, with the speaker of the House of Representatives becoming the real center of government as a quasi-prime minister. This did not happen and the presidency, having been damaged by three late nineteenth and early twentieth century assassinations (Lincoln, Garfield and McKinley) and one impeachment (Johnson), reasserted its political dominance by the early twentieth century through such figures as Theodore Roosevelt and Woodrow Wilson.


title: Head of state

text: In certain states under Marxist–Leninist constitutions of the constitutionally socialist state type inspired by the former Union of Soviet Socialist Republics (USSR) and its constitutive Soviet republics, real political power belonged to the sole legal party. In these states, there was no formal office of head of state, but rather the leader of the legislative branch was considered to be the closest common equivalent of a head of state as a natural person. In the Soviet Union this position carried such titles as "Chairman of the Central Executive Committee of the USSR"; "Chairman of the Presidium of the Supreme Soviet"; and in the case of the Soviet Russia "Chairman of the Central Executive Committee of the All-Russian Congress of Soviets" (pre-1922), and "Chairman of the Bureau of the Central Committee of the Russian SFSR" (1956–1966). This position may or may not have been held by the de facto Soviet leader at the moment. For example, Nikita Khrushchev never headed the Supreme Soviet but was First Secretary of the Central Committee of the Communist Party (party leader) and Chairman of the Council of Ministers (head of government).


title: Head of state

text: This may even lead to an institutional variability, as in North Korea, where, after the presidency of party leader Kim Il-sung, the office was vacant for years. The late president was granted the posthumous title (akin to some ancient Far Eastern traditions to give posthumous names and titles to royalty) of ""Eternal President"". All substantive power, as party leader, itself not formally created for four years, was inherited by his son Kim Jong-il. The post of president was formally replaced on 5 September 1998, for ceremonial purposes, by the office of President of the Presidium of the Supreme People's Assembly, while the party leader's post as chairman of the National Defense Commission was simultaneously declared "the highest post of the state", not unlike Deng Xiaoping earlier in the People's Republic of China.


title: Head of state

text: In China, under the current country's constitution, the Chinese President is a largely ceremonial office with limited power. However, since 1993, as a matter of convention, the presidency has been held simultaneously by the General Secretary of the Chinese Communist Party, the top leader in the one party system. The presidency is officially regarded as an institution of the state rather than an administrative post; theoretically, the President serves at the pleasure of the National People's Congress, the legislature, and is not legally vested to take executive action on its own prerogative.


title: Head of state

text: While clear categories do exist, it is sometimes difficult to choose which category some individual heads of state belong to. In reality, the category to which each head of state belongs is assessed not by theory but by practice.


title: Head of state

text: Constitutional change in Liechtenstein in 2003 gave its head of state, the Reigning Prince, constitutional powers that included a veto over legislation and power to dismiss the head of government and cabinet. It could be argued that the strengthening of the Prince's powers, vis-a-vis the Landtag (legislature), has moved Liechtenstein into the semi-presidential category. Similarly the original powers given to the Greek President under the 1974 Hellenic Republic constitution moved Greece closer to the French semi-presidential model.


title: Head of state

text: Another complication exists with South Africa, in which the president is in fact elected by the National Assembly (legislature) and is thus similar, in principle, to a head of government in a parliamentary system but is also, in addition, recognised as the head of state. The offices of president of Nauru and president of Botswana are similar in this respect to the South African presidency.


title: Head of state

text: Panama, during the military dictatorships of Omar Torrijos and Manuel Noriega, was nominally a presidential republic. However, the elected civilian presidents were effectively figureheads with real political power being exercised by the chief of the Panamanian Defense Forces.


title: Head of state

text: Historically, at the time of the League of Nations (1920–1946) and the founding of the United Nations (1945), India's head of state was the monarch of the United Kingdom, ruling directly or indirectly as Emperor of India through the Viceroy and Governor-General of India.


title: Head of state

text: Head of state is the highest-ranking constitutional position in a sovereign state. A head of state has some or all of the roles listed below, often depending on the constitutional category (above), and does not necessarily regularly exercise the most power or influence of governance. There is usually a formal public ceremony when a person becomes head of state, or some time after. This may be the swearing in at the inauguration of a president of a republic, or the coronation of a monarch.


title: Head of state

text: One of the most important roles of the modern head of state is being a living national symbol of the state; in hereditary monarchies this extends to the monarch being a symbol of the unbroken continuity of the state. For instance, the Canadian monarch is described by the government as being the personification of the Canadian state and is described by the Department of Canadian Heritage as the "personal symbol of allegiance, unity and authority for all Canadians".


title: Head of state

text: In many countries, official portraits of the head of state can be found in government offices, courts of law, or other public buildings. The idea, sometimes regulated by law, is to use these portraits to make the public aware of the symbolic connection to the government, a practice that dates back to medieval times. Sometimes this practice is taken to excess, and the head of state becomes the principal symbol of the nation, resulting in the emergence of a personality cult where the image of the head of state is the only visual representation of the country, surpassing other symbols such as the flag.


title: Head of state

text: Other common representations are on coins, postage and other stamps and banknotes, sometimes by no more than a mention or signature; and public places, streets, monuments and institutions such as schools are named for current or previous heads of state. In monarchies (e.g., Belgium) there can even be a practice to attribute the adjective "royal" on demand based on existence for a given number of years. However, such political techniques can also be used by leaders without the formal rank of head of state, even party - and other revolutionary leaders without formal state mandate.


title: Head of state

text: Heads of state often greet important foreign visitors, particularly visiting heads of state. They assume a host role during a state visit, and the programme may feature playing of the national anthems by a military band, inspection of military troops, official exchange of gifts, and attending a state dinner at the official residence of the host.


title: Head of state

text: At home, heads of state are expected to render lustre to various occasions by their presence, such as by attending artistic or sports performances or competitions (often in a theatrical honour box, on a platform, on the front row, at the honours table), expositions, national day celebrations, dedication events, military parades and war remembrances, prominent funerals, visiting different parts of the country and people from different walks of life, and at times performing symbolic acts such as cutting a ribbon, groundbreaking, ship christening, laying the first stone. Some parts of national life receive their regular attention, often on an annual basis, or even in the form of official patronage.


title: Head of state

text: The Olympic Charter (rule 55.3) of the International Olympic Committee states that the Olympic summer and winter games shall be opened by the head of state of the host nation, by uttering a single formulaic phrase as determined by the charter.


title: Head of state

text: As such invitations may be very numerous, such duties are often in part delegated to such persons as a spouse, a head of government or a cabinet minister or in other cases (possibly as a message, for instance, to distance themselves without rendering offence) just a military officer or civil servant.


title: Head of state

text: For non-executive heads of state there is often a degree of censorship by the politically responsible government (such as the head of government). This means that the government discreetly approves agenda and speeches, especially where the constitution (or customary law) assumes all political responsibility by granting the crown inviolability (in fact also imposing political emasculation) as in the Kingdom of Belgium from its very beginning; in a monarchy this may even be extended to some degree to other members of the dynasty, especially the heir to the throne.


title: Head of state

text: Below follows a list of examples from different countries of general provisions in law, which either designate an office as head of state or define its general purpose.


title: Head of state

text: In the majority of states, whether republics or monarchies, executive authority is vested, at least notionally, in the head of state. In presidential systems the head of state is the actual, de facto chief executive officer. Under parliamentary systems the executive authority is exercised by the head of state, but in practice is done so on the advice of the cabinet of ministers. This produces such terms as "Her Majesty's Government" and "His Excellency's Government." Examples of parliamentary systems in which the head of state is notional chief executive include Australia, Austria, Canada, Denmark, India, Italy, Norway, Spain and the United Kingdom.


title: Head of state

text: The few exceptions where the head of state is not even the nominal chief executive - and where supreme executive authority is according to the constitution explicitly vested in a cabinet - include the Czech Republic, Ireland, Israel, Japan and Sweden.


title: Head of state

text: The head of state usually appoints most or all the key officials in the government, including the head of government and other cabinet ministers, key judicial figures; and all major office holders in the civil service, foreign service and commissioned officers in the military. In many parliamentary systems, the head of government is appointed with the consent (in practice often decisive) of the legislature, and other figures are appointed on the head of government's advice.


title: Head of state

text: In practice, these decisions are often a formality. The last time the prime minister of the United Kingdom was unilaterally selected by the monarch was in 1963, when Queen Elizabeth II appointed Alec Douglas-Home on the advice of outgoing Prime Minister Harold Macmillan.


title: Head of state

text: In presidential systems, such as that of the United States, appointments are nominated by the president's sole discretion, but this nomination is often subject to confirmation by the legislature; and specifically in the US, the Senate has to approve senior executive branch and judicial appointments by a simple majority vote.


title: Head of state

text: The head of state may also dismiss office-holders. There are many variants on how this can be done. For example, members of the Irish Cabinet are dismissed by the president on the advice of the taoiseach; in other instances, the head of state may be able to dismiss an office holder unilaterally; other heads of state, or their representatives, have the theoretical power to dismiss any office-holder, while it is exceptionally rarely used. In France, while the president cannot force the prime minister to tender the resignation of the government, he can, in practice, request it if the prime minister is from his own majority. In presidential systems, the president often has the power to fire ministers at his sole discretion. In the United States, the unwritten convention calls for the heads of the executive departments to resign on their own initiative when called to do so.


title: Head of state

text: Some countries have alternative provisions for senior appointments: In Sweden, under the Instrument of Government of 1974, the Speaker of the Riksdag has the role of formally appointing the prime minister, following a vote in the Riksdag, and the prime minister in turn appoints and dismisses cabinet ministers at his/her sole discretion.


title: Head of state

text: Although many constitutions, particularly from the 19th century and earlier, make no explicit mention of a head of state in the generic sense of several present day international treaties, the officeholders corresponding to this position are recognised as such by other countries. In a monarchy, the monarch is generally understood to be the head of state.


title: Head of state

text: The Vienna Convention on Diplomatic Relations, which codified longstanding custom, operates under the presumption that the head of a diplomatic mission (i.e. ambassador or nuncio) of the sending state is accredited to the head of state of the receiving state. The head of state accredits (i.e. formally validates) their country's ambassadors (or rarer equivalent diplomatic mission chiefs, such as high commissioner or papal nuncio) through sending formal a Letter of Credence (and a Letter of Recall at the end of a tenure) to other heads of state and, conversely, receives the letters of their foreign counterparts. Without that accreditation, the chief of the diplomatic mission cannot take up their role and receive the highest diplomatic status. The role of a head of state in this regard, is codified in the Vienna Convention on Diplomatic Relations from 1961, which (as of 2017) 191 sovereign states has ratified.


title: Head of state

text: However, there are provisions in the Vienna Convention that a diplomatic agent of lesser rank, such as a chargé d'affaires, is accredited to the minister of foreign affairs (or equivalent).


title: Head of state

text: The head of state is often designated the high contracting party in international treaties on behalf of the state; signs them either personally or has them signed in his/her name by ministers (government members or diplomats); subsequent ratification, when necessary, may rest with the legislature. The treaties constituting the European Union and the European Communities are noteworthy contemporary cases of multilateral treaties cast in this traditional format, as are the accession agreements of new member states. However, rather than being invariably concluded between two heads of state, it has become common that bilateral treaties are in present times cast in an intergovernmental format, e.g., between the "Government of X and the Government of Y", rather than between "His Majesty the King of X and His Excellency the President of Y".


title: Head of state

text: In Canada, these head of state powers belong to the monarch as part of the royal prerogative, but the Governor General has been permitted to exercise them since 1947 and has done so since the 1970s.


title: Head of state

text: A head of state is often, by virtue of holding the highest executive powers, explicitly designated as the commander-in-chief of that nation's armed forces, holding the highest office in all military chains of command.


title: Head of state

text: In a constitutional monarchy or non-executive presidency, the head of state may de jure hold ultimate authority over the armed forces but will only normally, as per either written law or unwritten convention, exercise their authority on the advice of their responsible ministers: meaning that the de facto ultimate decision making on military manoeuvres is made elsewhere. The head of state will, regardless of actual authority, perform ceremonial duties related to the country's armed forces, and will sometimes appear in military uniform for these purposes; particularly in monarchies where also the monarch's consort and other members of a royal family may also appear in military garb. This is generally the only time a head of state of a stable, democratic country will appear dressed in such a manner, as statesmen and public are eager to assert the primacy of (civilian, elected) politics over the armed forces.


title: Head of state

text: In military dictatorships, or governments which have arisen from coups d'état, the position of commander-in-chief is obvious, as all authority in such a government derives from the application of military force; occasionally a power vacuum created by war is filled by a head of state stepping beyond the normal constitutional role, as King Albert I of Belgium did during World War I. In these and in revolutionary regimes, the head of state, and often executive ministers whose offices are legally civilian, will frequently appear in military uniform.


title: Head of state

text: Some countries with a parliamentary system designate officials other than the head of state with command-in-chief powers.


title: Head of state

text: It is usual that the head of state, particularly in parliamentary systems as part of the symbolic role, is the one who opens the annual sessions of the legislature, e.g. the annual State Opening of Parliament with the Speech from the Throne in Britain. Even in presidential systems the head of state often formally reports to the legislature on the present national status, e.g. the State of the Union address in the United States of America, or the State of the Nation Address in South Africa.


title: Head of state

text: Most countries require that all bills passed by the house or houses of the legislature be signed into law by the head of state. In some states, such as the United Kingdom, Belgium and Ireland, the head of state is, in fact, formally considered a tier of the legislature. However, in most parliamentary systems, the head of state cannot refuse to sign a bill, and, in granting a bill their assent, indicate that it was passed in accordance with the correct procedures. The signing of a bill into law is formally known as "promulgation". Some monarchical states call this procedure "royal assent".


title: Head of state

text: In some parliamentary systems, the head of state retains certain discretionary powers in relation to bills to be exercised. They may have authority to veto a bill until the houses of the legislature have reconsidered it, and approved it a second time; reserve a bill to be signed later, or suspend it indefinitely (generally in states with royal prerogative; this power is rarely used); refer a bill to the courts to test its constitutionality; refer a bill to the people in a referendum.


title: Head of state

text: If the head of state also serves as the chief executive, the head of state can politically control the necessary executive measures without which a proclaimed law can remain dead letter, sometimes for years or even forever.


title: Head of state

text: A head of state is often empowered to summon and dissolve the country's legislature. In most parliamentary systems, this is often done on the advice of the head of government. In some parliamentary systems, and in some presidential systems, however, the head of state may do so on their own initiative. Some states have fixed term legislatures, with no option of bringing forward elections (e.g., Article II, Section 3, of the U.S. Constitution). In other systems there are usually fixed terms, but the head of state retains authority to dissolve the legislature in certain circumstances. Where a head of government has lost support in the legislature, some heads of state may refuse a dissolution, where one is requested, thereby forcing the head of government's resignation.


title: Head of state

text: In a republic, the head of state nowadays usually bears the title of President, but some have or have had other titles. Titles commonly used by monarchs are King/Queen or Emperor/Empress, but also many other; e.g., Grand Duke, Prince, Emir and Sultan.


title: Head of state

text: Though president and various monarchical titles are most commonly used for heads of state, in some nationalistic regimes, the leader adopts, formally or de facto, a unique style simply meaning leader in the national language, e.g., Germany's single national socialist party chief and combined head of state and government, Adolf Hitler, as the "Führer" between 1934 and 1945.


title: Head of state

text: In 1959, when former British crown colony Singapore gained self-government, it adopted the Malay style "Yang di-Pertuan Negara" (literally means "head of state" in Malay) for its governor (the actual head of state remained the British monarch). The second and last incumbent of the office, Yusof bin Ishak, kept the style at 31 August 1963 unilateral declaration of independence and after 16 September 1963 accession to Malaysia as a state (so now as a constituent part of the federation, a non-sovereign level). After its expulsion from Malaysia on 9 August 1965, Singapore became a sovereign Commonwealth republic and installed Yusof bin Ishak as its first president.


title: Head of state

text: In 1959 after the resignation of Vice President Mohammad Hatta, President Sukarno abolished the position and title of vice-president, assuming the positions of Prime Minister and Head of Cabinet. He also proclaimed himself president for life (Indonesian: "Presiden Seumur Hidup Panglima Tertinggi"; ""panglima"" meaning "commander or martial figurehead", ""tertinggi"" meaning "highest"; roughly translated to English as "Supreme Commander of the Revolution"). He was praised as ""Paduka Yang Mulia"", a Malay honorific originally given to kings; Sukarno awarded himself titles in that fashion due to his noble ancestry.


title: Head of state

text: There are also a few nations in which the exact title and definition of the office of head of state have been vague. During the Chinese Cultural Revolution, following the downfall of Chinese President Liu Shaoqi, no successor was named, so the duties of the head of state were transferred collectively to the Vice Presidents Soong Ching-ling and Dong Biwu, then to the Standing Committee of the National People's Congress, but Chairman Mao Zedong was still the paramount leader. This situation was later changed: the President of the People's Republic of China is now the head of state. Although the presidency is a largely ceremonial office with limited power, the symbolic role of a head of state is now generally performed by Xi Jinping, who is also General Secretary of the Communist Party (Communist Party leader) and Chairman of the Central Military Commission (Supreme Military Command), making him the most powerful person in China.


title: Head of state

text: In North Korea, the late Kim Il-sung was named "Eternal President" 4 years after his death and the presidency was abolished. As a result, some of the duties previously held by the president were constitutionally delegated to the Chairman of the Standing Committee of the Supreme People's Assembly, who performs some of the roles of a head of state, such as accrediting foreign ambassadors and undertaking overseas visits. However, the "de jure" role of head of state lies within the President of the State Affairs Commission, currently Kim Jong-un, who as the General Secretary of the Workers' Party of Korea and Supreme Commander of the Armed Forces of North Korea, is the most powerful person in North Korea.


title: Head of state

text: There is debate as to whether Samoa was an elective monarchy or an aristocratic republic, given the comparative ambiguity of the title "O le Ao o le Malo" and the nature of the head of state's office.


title: Head of state

text: In some states the office of head of state is not expressed in a specific title reflecting that role, but constitutionally awarded to a post of another formal nature. Colonel Muammar Gaddafi initially ruled as combined head of state and briefly head of government of the Libyan Arab Republic, styled as Chairman of the Revolutionary Command Council. In 1977, the Libyan "Jamahiriya" ("state of the masses") replaced the previous republic, and in March 1979 the role of head of state was transferred to the Secretary-General of the General People's Congress (comparable to a Speaker); in practice however Gaddafi remained the "de facto" leader as "Guide of the Revolution" until his overthrow in 2011.


title: Head of state

text: Sometimes a head of state assumes office as a state becomes legal and political reality, before a formal title for the highest office is determined; thus in the since 1 January 1960 independent republic Cameroon ("Cameroun", a former French colony), the first president, Ahmadou Babatoura Ahidjo, was at first not styled but 'merely' known as (French for "head of state") until 5 May 1960. In Uganda, Idi Amin the military leader after the coup of 25 January 1971 was formally styled "military head of state" till 21 February 1971, only from then on as regular (but unconstitutional, unelected) president.


title: Head of state

text: In certain cases a special style is needed to accommodate imperfect statehood, e.g., the title "Sadr-i-Riyasat" was used in Kashmir after its accession to India, and the Palestine Liberation Organization leader, Yasser Arafat, was styled the first "President of the Palestinian National Authority" in 1994. In 2008, the same office was restyled as "President of the State of Palestine".


title: Head of state

text: In medieval Catholic Europe, it was universally accepted that the Pope ranked first among all rulers and was followed by the Holy Roman Emperor. The Pope also had the sole right to determine the precedence of all others. This principle was first challenged by a Protestant ruler, Gustavus Adolphus of Sweden and was later maintained by his country at the Congress of Westphalia. Great Britain would later claim a break of the old principle for the Quadruple Alliance in 1718. However, it was not until the 1815 Congress of Vienna, when it was decided (due to the abolition of the Holy Roman Empire in 1806 and the weak position of France and other catholic states to assert themselves) and remains so to this day, that all sovereign states are treated as equals, whether monarchies or republics. On occasions when multiple heads of state or their representatives meet, precedence is by the host usually determined in alphabetical order (in whatever language the host determines, although French has for much of the 19th and 20th centuries been the "lingua franca" of diplomacy) or by date of accession. Contemporary international law on precedence, built upon the universally admitted principles since 1815, derives from the Vienna Convention on Diplomatic Relations (in particular, articles 13, 16.1 and Appendix iii).


title: Head of state

text: Niccolò Machiavelli used "Prince" () as a generic term for the ruler, similar to contemporary usage of "head of state", in his classical treatise "The Prince", originally published in 1532: in fact that particular literary genre it belongs to is known as Mirrors for princes. Thomas Hobbes in his "Leviathan" (1651) used the term "Sovereign". In Europe the role of a monarchs has gradually transitioned from that of a sovereign rulerin the sense of Divine Right of Kings as articulated by Jean Bodin, Absolutism and the "L'etat c'est moi"to that of a constitutional monarch; parallel with the conceptual evolution of sovereignty from merely the personal rule of a single person, to Westphalian sovereignty (Peace of Westphalia ending both the Thirty Years' War & Eighty Years' War) and popular sovereignty as in consent of the governed; as shown in the Glorious Revolution of 1688 in England & Scotland, the French Revolution in 1789, and the German Revolution of 1918–1919. The monarchies who survived through this era were the ones who were willing to subject themselves to constitutional limitations.


title: Head of state

text: Whenever a head of state is not available for any reason, constitutional provisions may allow the role to fall temporarily to an assigned person or collective body. In a republic, this is - depending on provisions outlined by the constitution or improvised - a vice-president, the chief of government, the legislature or its presiding officer. In a monarchy, this is usually a regent or collegial regency (council). For example, in the United States the vice-president acts when the president is incapacitated, and in the United Kingdom the queen's powers may be delegated to counselors of state when she is abroad or unavailable. Neither of the two co-princes of Andorra is resident in Andorra; each is represented in Andorra by a delegate, though these persons hold no formal title.


title: Head of state

text: There are also several methods of head of state succession in the event of the removal, disability or death of an incumbent head of state.


title: Head of state

text: In exceptional situations, such as war, occupation, revolution or a coup d'état, constitutional institutions, including the symbolically crucial head of state, may be reduced to a figurehead or be suspended in favour of an emergency office (such as the original Roman dictator) or eliminated by a new "provisionary" regime, such as a collective of the junta type, or removed by an occupying force, such as a military governor (an early example being the Spartan Harmost).


title: Head of state

text: In early modern Europe, a single person was often monarch simultaneously of separate states. A composite monarchy is a retrospective label for those cases where the states were governed entirely separately. Of contemporary terms, a personal union had less government co-ordination than a real union. One of the two co-princes of Andorra is the president of France.


title: Head of state

text: The Commonwealth realms share a monarch, currently Charles III. In the realms other than the United Kingdom, a governor-general ("governor general" in Canada) is appointed by the sovereign, usually on the advice of the relevant prime minister (although sometimes it is based on the result of a vote in the relevant parliament, which is the case for Papua New Guinea and the Solomon Islands), as a representative and to exercise almost all the Royal Prerogative according to established constitutional authority. In Australia the present king is generally assumed to be head of state, since the governor-general and the state governors are defined as his "representatives". However, since the governor-general performs almost all national regal functions, the governor-general has occasionally been referred to as head of state in political and media discussion. To a lesser extent, uncertainty has been expressed in Canada as to which officeholder—the monarch, the governor general, or both—can be considered the head of state. New Zealand, Papua New Guinea, and Tuvalu explicitly name the monarch as their head of state (though Tuvalu's constitution states that "references in any law to the Head of State shall be read as including a reference to the governor-general"). Governors-general are frequently treated as heads of state on state and official visits; at the United Nations, they are accorded the status of head of state in addition to the sovereign.


title: Head of state

text: An example of a governor-general departing from constitutional convention by acting unilaterally (that is, without direction from ministers, parliament, or the monarch) occurred in 1926, when Canada's governor general refused the head of government's formal advice requesting a dissolution of parliament and a general election. In a letter informing the monarch after the event, the Governor General said: "I have to await the verdict of history to prove my having adopted a wrong course, and this I do with an easy conscience that, right or wrong, I have acted in the interests of Canada and implicated no one else in my decision."


title: Head of state

text: Another example occurred when, in the 1975 Australian constitutional crisis, the governor-general unexpectedly dismissed the prime minister in order to break a stalemate between the House of Representatives and Senate over money bills. The governor-general issued a public statement saying he felt it was the only solution consistent with the constitution, his oath of office, and his responsibilities, authority, and duty as governor-general. A letter from the queen's private secretary at the time, Martin Charteris, confirmed that the only person competent to commission an Australian prime minister was the governor-general and it would not be proper for the monarch to personally intervene in matters that the Constitution Act so clearly places within the governor-general's jurisdiction.


title: Head of state

text: Other Commonwealth realms that are now constituted with a governor-general as the viceregal representative of Charles III are: Antigua and Barbuda, the Bahamas, Belize, Grenada, Jamaica, New Zealand, Saint Kitts and Nevis, Saint Lucia, and Saint Vincent and the Grenadines.


title: Head of state

text: Since antiquity, various dynasties or individual rulers have claimed the right to rule by divine authority, such as the Mandate of Heaven and the divine right of kings. Some monarchs even claimed divine ancestry, such as Egyptian pharaohs and Sapa Incas, who claimed descent from their respective sun gods and often sought to maintain this bloodline by practising incestuous marriage. In Ancient Rome, during the Principate, the title ('divine') was conferred (notably posthumously) on the emperor, a symbolic, legitimating element in establishing a de facto dynasty.


title: Head of state

text: In Roman Catholicism, the pope was once sovereign pontiff and head of state, first, of the politically important Papal States. After Italian unification, the pope remains head of state of Vatican City. Furthermore, the bishop of Urgell is "ex officio" one of the two co-princes of Andorra. In the Church of England, the reigning monarch holds the title Defender of the Faith and acts as supreme governor of the Church of England, although this is purely a symbolic role.


title: Head of state

text: During the early period of Islam, caliphs were spiritual and temporal absolute successors of the prophet Mohammed. Various political Muslim leaders since have styled themselves "Caliph" and served as dynastic heads of state, sometimes in addition to another title, such as the Ottoman Sultan. Historically, some theocratic Islamic states known as "imamates" have been led by imams as head of state, such as in what is now Oman, Yemen, and Saudi Arabia.


title: Head of state

text: In the Islamic Republic of Iran, the Supreme Leader, at present Ali Khamenei serves as head of state. The Aga Khans, a unique dynasty of temporal/religious leadership, leading the Nizari offshoot of Shia Islam in Central and South Asia, once ranking among British India's princely states, continue to the present day.


title: Head of state

text: In Hinduism, certain dynasties adopted a title expressing their positions as "servant" of a patron deity of the state, but in the sense of a viceroy under an absentee god-king, ruling "in the name of" the patron god(ess), such as Patmanabha Dasa (servant of Vishnu) in the case of the Maharaja of Travancore.


title: Head of state

text: From the time of the 5th Dalai Lama until the political retirement of the 14th Dalai Lama in 2011, Dalai Lamas were both political and spiritual leaders ("god-king") of Tibet.


title: Head of state

text: Outer Mongolia, the former homeland of the imperial dynasty of Genghis Khan, was another lamaist theocracy from 1585, using various styles, such as tulku. The establishment of the Communist Mongolian People's Republic replaced this regime in 1924.


title: Head of state

text: A collective head of state can exist in republics (internal complexity), e.g., nominal triumvirates, the Directoire, the seven-member Swiss Federal Council (where each member acts in turn as president for one year), Bosnia and Herzegovina with a three-member presidency from three nations, San Marino with two "captains-regent" which maintains the tradition of Italian medieval republics that had always had an even number of consuls. A diarchy, in which two rulers is the constitutional norm, may be distinguished from a coregency, in which a monarchy experiences an exceptional period of multiple rulers.


title: Head of state

text: In the Roman Republic there were two heads of state, styled consul, both of whom alternated months of authority during their year in office, similarly there was an even number of supreme magistrates in the Italic republics of Ancient Age. In the Athenian Republic there were nine supreme magistrates, styled archons. In Carthage there were two supreme magistrates, styled kings or suffetes (judges). In ancient Sparta there were two hereditary kings, belonging to two dynasties. In the Soviet Union the Central Executive Committee of the Congress of Soviets (between 1922 and 1938) and later the Presidium of the Supreme Soviet (between 1938 and 1989) served as the collective head of state. After World War II the Soviet model was subsequently adopted by almost all countries belonged to its sphere of influence. Czechoslovakia remained the only country among them that retained an office of president as a form of a single head of state throughout this period; Poland and Hungary, which initially had western-style constitutions (and therefore, western-style presidencies), switched to the presidium model with the adoption of new Soviet-influenced constitutions; Romania, which was a monarchy before the Soviet takeover, was the only country to move to a unitary presidency from a collective head of state, a move done by dictator Nicolae Ceausescu in 1974. A modern example of a collective head of state is the Sovereignty Council of Sudan, the interim ruling council of Sudan. The Sovereignty Council comprises 11 ministers, who together have exercised all governmental functions for Sudan since the fall of President Omar Al-Bashir. Decisions are made either by consensus or by a super majority vote (8 members).


title: Head of state

text: Such arrangements are not to be confused with supranational entities which are not states and are not defined by a common monarchy but may (or not) have a symbolic, essentially protocollary, titled highest office, e.g., Head of the Commonwealth (held by the British crown, but not legally reserved for it) or 'Head of the Arab Union' (14 February - 14 July 1958, held by the Hashemite King of Iraq, during its short-lived Federation with Jordan, its Hashemite sister-realm).


title: Head of state

text: The National Government of the Republic of China, established in 1928, had a panel of about 40 people as collective head of state. Though beginning that year, a provisional constitution made the Kuomintang the sole government party and the National Government bound to the instructions of the Central Executive Committee of that party.


title: Head of state

text: The position of head of state can be established in different ways, and with different sources of legitimacy.


title: Head of state

text: Power can come from force, but formal legitimacy is often established, even if only by fictitious claims of continuity (e.g., a forged claim of descent from a previous dynasty). There have been cases of sovereignty granted by deliberate act, even when accompanied by orders of succession (as may be the case in a dynastic split). Such grants of sovereignty are usually forced, as is common with self-determination granted after nationalist revolts. This occurred with the last Attalid king of Hellenistic Pergamon, who by testament left his realm to Rome to avoid a disastrous conquest.


title: Head of state

text: Under a theocracy, perceived divine status translated into earthly authority under divine law. This can take the form of supreme divine authority above the state's, granting a tool for political influence to a priesthood. In this way, the Amun priesthood reversed the reforms of Pharaoh Akhenaten after his death. The division of theocratic power can be disputed, as happened between the Pope and Holy Roman Emperor in the investiture conflict when the temporal power sought to control key clergy nominations in order to guarantee popular support, and thereby his own legitimacy, by incorporating the formal ceremony of unction during coronation.


title: Head of state

text: The notion of a social contract holds that the nation—either the whole people or the electorate—gives a mandate, through acclamation or election.


title: Head of state

text: Individual heads of state may acquire their position by virtue of a constitution. An example is the Seychelles, as the 1976 Independence Constitution of the Seychelles, Article 31, stated that James Mancham would be the first President of the Republic by name, rather than by the fact he was the Prime Minister of colonial Seychelles immediately before independence.


title: Head of state

text: The position of a monarch is usually hereditary, but in constitutional monarchies, there are usually restrictions on the incumbent's exercise of powers and prohibitions on the possibility of choosing a successor by other means than by birth. In a hereditary monarchy, the position of monarch is inherited according to a statutory or customary order of succession, usually within one royal family tracing its origin through a historical dynasty or bloodline. This usually means that the heir to the throne is known well in advance of becoming monarch to ensure a smooth succession. However, many cases of uncertain succession in European history have often led to wars of succession.


title: Head of state

text: Primogeniture, in which the eldest child of the monarch is first in line to become monarch, is the most common system in hereditary monarchy. The order of succession is usually affected by rules on gender. Historically "agnatic primogeniture" or "patrilineal primogeniture" was favoured, that is inheritance according to seniority of birth among the sons of a monarch or head of family, with sons and their male issue inheriting before brothers and their issue, and male-line males inheriting before females of the male line. This is the same as semi-Salic primogeniture. Complete exclusion of females from dynastic succession is commonly referred to as application of the Salic law (see "Terra salica").


title: Head of state

text: Before primogeniture was enshrined in European law and tradition, kings would often secure the succession by having their successor (usually their eldest son) crowned during their own lifetime, so for a time there would be two kings in coregency – a senior king and a junior king. Examples include Henry the Young King of England and the early Direct Capetians in France.


title: Head of state

text: Sometimes, however, primogeniture can operate through the female line. In some systems a female may rule as monarch only when the male line dating back to a common ancestor is exhausted. In 1980, Sweden, by rewriting its 1810 Act of Succession, became the first European monarchy to declare equal (full cognatic) primogeniture, meaning that the eldest child of the monarch, whether female or male, ascends to the throne. Other European monarchies (such as the Netherlands in 1983, Norway in 1990 and Belgium in 1991) have since followed suit. Similar reforms were proposed in 2011 for the United Kingdom and the other Commonwealth realms, which came into effect in 2015 after having been approved by all of the affected nations. Sometimes religion is affected; under the Act of Settlement 1701 all Roman Catholics and all persons who have married Roman Catholics are ineligible to be the British monarch and are skipped in the order of succession.


title: Head of state

text: In some monarchies there may be liberty for the incumbent, or some body convening after the death of the monarch, to choose from eligible members of the ruling house, often limited to legitimate descendants of the dynasty's founder. Rules of succession may be further limited by state religion, residency, equal marriage or even permission from the legislature.


title: Head of state

text: Other hereditary systems of succession included tanistry, which is semi-elective and gives weight to merit and Agnatic seniority. In some monarchies, such as Saudi Arabia, succession to the throne usually first passes to the monarch's next eldest brother, and only after that to the monarch's children (agnatic seniority).


title: Head of state

text: Election usually is the constitutional way to choose the head of state of a republic, and some monarchies, either directly through popular election, indirectly by members of the legislature or of a special college of electors (such as the Electoral College in the United States), or as an exclusive prerogative. Exclusive prerogative allows the heads of states of constituent monarchies of a federation to choose the head of state for the federation among themselves, as in the United Arab Emirates and Malaysia. The Pope, head of state of Vatican City, is chosen by previously appointed cardinals under 80 years of age from among themselves in a papal conclave.


title: Head of state

text: A head of state can be empowered to designate his successor, such as Lord Protector of the Commonwealth Oliver Cromwell, who was succeeded by his son Richard.


title: Head of state

text: A head of state may seize power by force or revolution. This is not the same as the use of force to "maintain" power, as is practised by authoritarian or totalitarian rulers. Dictators often use democratic titles, though some proclaim themselves monarchs. Examples of the latter include Emperor Napoleon I of France and King Zog of Albania. In Spain, general Francisco Franco adopted the formal title "Jefe del Estado", or Chief of State, and established himself as regent for a vacant monarchy. Uganda's Idi Amin was one of several who named themselves President for Life.


title: Head of state

text: A foreign power can establishing a branch of their own dynasty, or one friendly to their interests. This was the outcome of the Russo-Swedish War from 1741 to 1743 where the Russian Empress made the imposition of her relative Adolf Frederick as the heir to the Swedish Throne, to succeed Frederick I who lacked legitimate issue, as a peace condition.


title: Head of state

text: Apart from violent overthrow, a head of state's position can be lost in several ways, including death, another by expiration of the constitutional term of office, abdication, or resignation. In some cases, an abdication cannot occur unilaterally, but comes into effect only when approved by an act of parliament, as in the case of British King Edward VIII. The post can also be abolished by constitutional change; in such cases, an incumbent may be allowed to finish their term. Of course, a head of state position will cease to exist if the state itself does.


title: Head of state

text: Heads of state generally enjoy widest inviolability, although some states allow impeachment, or a similar constitutional procedure by which the highest legislative or judicial authorities are empowered to revoke the head of state's mandate on exceptional grounds. This may be a common crime, a political sin, or an act by which the head of state violates such provisions as an established religion mandatory for the monarch. By similar procedure, an original mandate may be declared invalid.


title: Head of state

text: Effigies, memorials and monuments of former heads of state can be designed to represent the history or aspirations of a state or its people, such as the equestrian bronze sculpture of Kaiser Wilhelm I, first Emperor of a unified Germany erected in Berlin at the end of the nineteenth century; or the Victoria Memorial erected in front of Buckingham Palace London, commemorating Queen Victoria and her reign (1837–1901), and unveiled in 1911 by her grandson, King George V; or the monument, placed in front of the Victoria Memorial Hall, Kolkata (Calcutta) (1921), commemorating Queen Victoria's reign as Empress of India from 1876. Another, twentieth century, example is the Mount Rushmore National Memorial, a group sculpture constructed (1927–1941) on a conspicuous skyline in the Black Hills of South Dakota (40th state of the Union, 1889), in the midwestern United States, representing the territorial expansion of the United States in the first 130 years from its founding, which is promoted as the "Shrine of Democracy".


title: Head of state

text: Former presidents of the United States, while holding no political powers per se, sometimes continue to exert influence in national and world affairs.


title: Head of state

text: A monarch may retain his style and certain prerogatives after abdication, as did King Leopold III of Belgium, who left the throne to his son after winning a referendum which allowed him to retain a full royal household deprived him of a constitutional or representative role. Napoleon transformed the Italian principality of Elba, where he was imprisoned, into a miniature version of his First Empire, with most trappings of a sovereign monarchy, until his "Cent Jours" escape and reseizure of power in France convinced his opponents, reconvening the Vienna Congress in 1815, to revoke his gratuitous privileges and send him to die in exile on barren Saint Helena.


title: Head of state

text: By tradition, deposed monarchs who have not freely abdicated continue to use their monarchical titles as a courtesy for the rest of their lives. Hence, even after Constantine II ceased to be "King of the Hellenes", it is still common to refer to the deposed king and his family as if Constantine II were still on the throne, as many European royal courts and households do in guest lists at royal weddings, as in Sweden in 2010, Britain in 2011 and Luxembourg in 2012. The current Hellenic Republic opposes the right of their deposed monarch and former royal family members to be referred to by their former titles or bearing a surname indicating royal status, and has enacted legislation which hinders acquisition of Greek citizenship unless those terms are met. The former king brought this issue, along with property ownership issues, before the European Court of Human Rights for alleged violations of the European Convention on Human Rights, but lost with respect to the name issue.


title: Head of state

text: However, some other states have no problem with deposed monarchs being referred to by their former title, and even allow them to travel internationally on the state's diplomatic passport.


title: Head of state

text: The Italian constitution provides that a former president of the Republic takes the title President Emeritus of the Italian Republic and he or she is also a senator for life, and enjoys immunity, flight status and official residences certain privileges.


title: Juhi Chawla

text: Juhi Chawla (born 13 November 1967) is an Indian actress, film producer and entrepreneur. She established herself as one of the leading actresses of Hindi cinema from the late 1980s through the early 2000s. Recognised for her comic timing and vivacious on-screen persona, she is the recipient of several accolades, including two Filmfare Awards.


title: Juhi Chawla

text: After winning the 1984 Miss India beauty pageant at age 16, Chawla made her acting debut with a brief appearance in the film "Sultanat" (1986), and had her breakthrough role in the tragic romance film "Qayamat Se Qayamat Tak" (1988), which earned her the Filmfare Award for Best Female Debut. She propelled her career forward with starring roles in "Lootere" (1993), "Aaina" (1993), "Darr" (1993), and "Hum Hain Rahi Pyar Ke" (1993), for which she won the Filmfare Award for Best Actress. Further success came in 1997 with "Deewana Mastana", "Yes Boss", and "Ishq". The following decade, Chawla was willing to play against type and began working with independent filmmakers in art-house projects, garnering critical acclaim for her performances in "Jhankaar Beats" (2003), "3 Deewarein" (2003), "My Brother Nikhil" (2005), "I Am" (2011) and "Gulaab Gang" (2014). Moreover, she starred in several Punjabi films, including the biopics "Shaheed Udham Singh" (2000), "Des Hoyaa Pardes" (2004), "" (2006) and "Sukhmani – Hope for Life" (2010).


title: Juhi Chawla

text: Chawla has been married to industrialist Jay Mehta since 1995, with whom she has two children. Along with her husband and Shah Rukh Khan, she is the co-owner of the Indian Premier League cricket team Kolkata Knight Riders. Along with Khan, she co-founded the production company Dreamz Unlimited, which produced three films, starting with their self-starring "Phir Bhi Dil Hai Hindustani" (2000). Among her television work, she was a talent judge on the third season of the dance reality show "Jhalak Dikhhla Jaa".


title: Juhi Chawla

text: Juhi Chawla was born on 13 November 1967 and raised in Ambala, Haryana, India. Her father was an officer of the Indian Revenue Service (IRS). She completed her schooling at Fort Convent School, Bombay (present-day Mumbai), and graduated from Sydenham College, Bombay. Chawla was the winner of the Miss India title in 1984. She also won the Best Costume Award at the Miss Universe contest in 1984.


title: Juhi Chawla

text: Her first major role in Bollywood was in "Qayamat Se Qayamat Tak" in 1988, in which she starred with Aamir Khan. The film, a modern-day adaption of Shakespeare's "Romeo and Juliet", was both a major critical and commercial success, with Khan and Chawla becoming "overnight stars". It won the Filmfare Award for Best Film, and Chawla became the first actress to win the Filmfare Award for Lux New Face of the Year, also receiving her first nomination for Best Actress. Chawla's pairing with Aamir Khan and their on-screen chemistry was often cited by the media as successful. The film has since attained a cult status, with "The Times of India" ranking it amongst the "Top 25 Must See Bollywood Films", calling it "one of the landmark films of Hindi cinema" and crediting it with making "Aamir Khan and Juhi Chawla household names". Premankur Biswas of "First Post" wrote in a retrospective review, "Juhi Chawla, with her flouncy ghagra and passive but assertive demeanor was an early predecessor to the sexually liberated Bollywood heroines of today. She wore what she wanted and initiated a relationship with the man she desired".


title: Juhi Chawla

text: In 1990, she starred in "Pratibandh". She also received her second Best Actress nomination at Filmfare for the film. Her other releases that year included the family drama "Swarg" alongside Rajesh Khanna and Govinda, which marked the first of several collaborations with director David Dhawan. In 1992, she appeared in "Bol Radha Bol" alongside Rishi Kapoor, for which she received her third Filmfare nomination for Best Actress. Another pairing with Aamir Khan in "Daulat Ki Jung" resulted in negative reviews.


title: Juhi Chawla

text: In 1993, Chawla appeared in four films. Her first release was "Lootere", directed by Dharmesh Darshan and starring Sunny Deol, Naseeruddin Shah, Chunkey Pandey and Anupam Kher. She played a young woman who receives witness protection through the service of a bodyguard, played by Deol, with whom she eventually falls in love. She was cast in two movies produced by Yash Chopra. The first was "Aaina", which saw Chawla and Amrita Singh play sisters falling for the same man, played by Jackie Shroff. Her third film that year was Mahesh Bhatt's romantic comedy "Hum Hain Rahi Pyar Ke" opposite Aamir Khan, which was a success with both critics and audiences. Her performance as a Tamilian runaway, which required her to master Tamil language and dialect, met with acclaim and established her as a comic actress. Writing for "The Indian Express", Udaya Tara Nayar noted that she played her role "to perfection". She won a Filmfare Award for Best Actress for her work. The last film she appeared in that year was the thriller "Darr", directed by Yash Chopra. The film was one of the highest-grossing films of the year, making it Chawla's fourth consecutive box office hit of the year. "Darr" was also a major critical success, winning several awards including the National Film Award for Best Popular Film Providing Wholesome Entertainment. She played Kiran, a young woman about to get married with her fiancé (Deol) when she becomes the object of a young man's (Khan) obsession.


title: Juhi Chawla

text: Subsequently, she played leading roles in several films, most notably as Saraswati in David Dhawan's "Andaz" (1994), Laxmi in Surendra Kumar Bohra's "Saajan Ka Ghar" (1994), Bela in Rajiv Mehra's "Ram Jaane" (1995), Sandhya in "Naajayaz" (1995), which marked one of her rare collaborations with Ajay Devgn, and Kiran in David Dhawan and Boney Kapoor's "Loafer" (1996), and all of them emerged as critical and commercial successes. She received critical acclaim for her performance as a battered wife in Abbas Mustan's thriller "Daraar" (1996), and she received a nomination of Filmfare Award for Best Actress for her performance in the film. The film was not a major commercial success, but Chawla's performance earned her positive reviews. She was also offered Karisma Kapoor's role in "Dil To Pagal Hai" (1997), but she turned it down. Chawla's career had hit its peak, and she regained mainstream success in 1997 with the romantic comedies "Yes Boss", "Deewana Mastana" and "Ishq", all becoming box office hits. "Ishq" became one of the top-earners of the year, and earned critical praise for the performances of its four leads.


title: Juhi Chawla

text: In the romantic comedy "Yes Boss", she played a model who becomes the love interest of an ad agency owner and his ambitious employee, played by Aditya Pancholi and Shah Rukh Khan, respectively. "Yes Boss" opened to favourable reviews and did well commercially, and Chawla received a seventh Filmfare nomination for her portrayal, which was described by "Screen" as "spirited". In a 1998 retrospective review for "The Times of India", Khushboo Tiwari called it "a quintessential ‘90s romcom" and took note of Chawla's chemistry with Khan. In the comedy "Deewana Mastana", Chawla played Dr. Neha Sharma, love interest to both Kapoor and Govinda and ends up marrying Salman Khan. The film was a commercial success. Her other release of the year was "Mr and Mrs Khiladi" alongside Akshay Kumar. The film turned out to be an average grosser.


title: Juhi Chawla

text: In 1998, she appeared once again alongside Shah Rukh Khan in "Duplicate", the film was produced by Yash Johar and directed by Mahesh Bhatt. The film though was the 12th highest grosser of the year, but underperformed at the box office upon its release. The same year, she appeared in Hrishikesh Mukherjee's swan song "Jhooth Bole Kauwa Kaate" alongside Anil Kapoor; the film was received well by critics for its reminiscence of Mukherjee's films, with one critic calling it a "a classy comedy". The same year, she also appeared in Priyadarshan's rural drama "Saat Rang Ke Sapne" opposite Arvind Swamy. The film underperformed at the box-office, but Khalid Mohamed wrote of her that she is "only saving grace. Lovely to look at and an instinctive actress, she's a likeable as ever." The same year, she starred in the Malayalam detective comedy "Harikrishnans" opposite Mohanlal and Mammootty. "Harikrishnans" was a commercial success.


title: Juhi Chawla

text: In 1999, she appeared in "Arjun Pandit" alongside Sunny Deol. She played a woman who seeks revenge in the film and described her character as "a role with negative shades". The critical reception to the film was lukewarm, but Chawla's work was better received. The film was the thirteenth highest grossing film of 1999, and emerged as a moderate critical and commercial success. The same year, she also starred opposite Sanjay Dutt in the adventure film "Safari", a critical and commercial failure. She worked free of charge in the Punjabi-language biographical film "Shaheed Udham Singh", based on the life of Udham Singh.


title: Juhi Chawla

text: In 2000, alongside Shah Rukh Khan and Aziz Mirza, she opened a production company called Dreamz Unlimited. The romantic comedy "Phir Bhi Dil Hai Hindustani" was the company's first production starring Chawla and Khan. Upon release, the film underperformed at the box office, though over the years it has been appreciated for its bold theme on media wars. Chawla's performance as the journalist Ria Banarjee received appreciation from the critics. Rediff critic Swapna Mitter wrote, "This is probably one of Juhi's best performances. She has never looked better... and once again, like "Hum Hain Rahi Pyar Ke", she shows a flair for comedy." Her other release of the year was Rakesh Roshan's delayed "", which was in the making for over five years and failed upon release. She played a small role in "Gang".


title: Juhi Chawla

text: In 2001, she appeared in the action comedy "One 2 Ka 4" with Shah Rukh Khan, in their seventh collaboration and with Jackie Shroff, the film was a flop at the box office. Chawla played three roles in the film; a haryanvi maid, a bar dancer and an undercover cop. While the film was noticed for its serious content, her comedic performance won acclaim from several critics. Vinayak Chakravorty wrote, "But the winner here is Juhi — that vintage comic flair of "Hum Hain Raahi Pyaar Ke" almost comes back from the dead." Similarly, Nikhat Kazmi of "The Times of India" "The only saving grace in this sea of confusion is Juhi. As a fast talking Haryanvi loudmouth who has the hots for her 'Ricky Martin' (Shahrukh), she is an absolute delight." "The Hindu" agreed with this observation, further noting her "unfailing sense of humour" and timing, which "few can match". Another release of the year was the comedy "Aamdani Atthani Kharcha Rupaiyaa" opposite Govinda. Around the same time, she signed a Kannada film "Adhishesha", in which she was to star opposite her "Premaloka" co–star V. Ravichandran. But due to uncanny reasons, the film was later shelved.


title: Juhi Chawla

text: Having taken a one-year break from film work, Chawla started appearing in independent and art films, and her work included critically acclaimed films "Jhankaar Beats", "3 Deewarein" (both 2003), "7½ Phere" and "My Brother Nikhil" (both 2005), and "Bas Ek Pal" (2006). "Jhankaar Beats", a musical comedy and a tribute to music director R. D. Burman, saw her play the wife of an aspiring musician. She won a Star Screen Award for Best Supporting Actress for "3 Deewarein", which earned her positive reviews. Director Kukunoor wrote the film with Chawla in mind, aspiring to change her image. Robert Koehler of "Variety" wrote, "Chawla gradually settles into a role that contains at least three different character layers to it." Chawla said "3 Deewarein" was a mould-breaking film in her career, and spoke of the revealing experience in making non-mainstream films which require a more realistic approach to acting and minimal use of make-up. She acted opposite Gurdas Mann in the Punjabi-language feature "Des Hoyaa Pardes" (2004) which was warmly received. She said she chose the part because upon reading the script, she identified a "tremendous scope for performance". The film won the National Film Award for Best Feature Film in Punjabi.


title: Juhi Chawla

text: Set in Goa between 1986 and 1994, Onir's "My Brother Nikhil" centers on the character of Nikhil (played by Sanjay Suri), a young man who is tested HIV-positive. Chawla co-starred as Anamika Kapoor, a schoolteacher by profession and Nikhil's loving and supportive elder sister, who accepts his same-gender partner and stands by his side through his struggle. The film opened to a welcome reception by critics, and Chawla's performance was particularly praised. Khalid Mohamed was highly approving of her portrayal: "Above all, Juhi Chawla is perfect. Her effortless blend of conflicting emotions is what A-class acting is all about. Ms Chawla is a diamond in this little gem of a movie." She starred alongside Irfan Khan in "7½ Phere". "Hindustan Times" commended her comic performance.


title: Juhi Chawla

text: In 2006, she appeared in the ensemble drama "" directed by Nikhil Advani. She collaborated with Onir once again with in the drama "Bas Ek Pal" (2006) alongside Urmila Matondkar and Sanjay Suri. She played Ira Malhotra, a battered wife who refuses to leave her possessive husband for religious reasons. The film opened to positive reviews. Subhash K. Jha wrote of Chawla that she "uses her ability to portray hurt and guilt with minimum effort." The same year she starred in another Punjabi film, the historical drama "", which won a National Film Award. According to the BBC, the film "bears the hallmarks of a quality production". The film is based on the life of Punjabi poet Waris Shah during the times he wrote the poem "Heer".


title: Juhi Chawla

text: Chawla and Manoj Bajpayee played a married couple in Ganesh Acharya's drama "Swami" (2007), which follows their financial struggles to secure proper education for their intelligent son. Reviews of the film were varied. Tanveer Bookwala of Rediff appreciated the film for its simple story and for giving the lead pair "the chance to be unconventional and subtle and they do not fail to deliver."


title: Juhi Chawla

text: Chawla then appeared in Ravi Chopra's "Bhoothnath" (2008) with Amitabh Bachchan, in which she made her singing debut with the song "Chalo Jaane Do", the film was a moderate success and Chawla was appreciated for her role. Manish Gajjar from BBC wrote, "Juhi Chawla's brilliant comic timing as Banku's mum has you in stitches." Another film called "Krazzy 4" with Irfan Khan and Arshad Warsi was released in 2008, the film failed to do well at the box office. In 2009, she appeared in a cameo appearance in "Luck By Chance" to play a comic part for which she dyed her hair blonde. The film and Chawla's performance got highly positive reviews and got a good opening at the box office.


title: Juhi Chawla

text: In 2011, Chawla starred in Onir's critically acclaimed anthology film "I Am" (2010). Unfolded in several chapters, the film starred Chawla alongside Manisha Koirala in an episode named "I Am Megha". She played the title role of a Kashmiri Pandit who travels back to her hometown in Srinagar, having been driven out of it years ago. For her performance, Chawla was awarded the Best Actress award at the 13th London Asian Film Festival and Award for Excellence in Hindi Cinema at the Asiavision Movie Awards. Her performance also earned her a nomination for the Filmfare Award for Best Supporting Actress. Rajeev Masand wrote, "Juhi Chawla is a portrait of suppressed vulnerability as she confronts her feelings about an old home and an old friend."


title: Juhi Chawla

text: Chawla next starred in the action comedy "Son of Sardaar" (2012) opposite Sanjay Dutt, which was poorly received by critics. "Live Mint" called it "the worst portrayal of Punjabiyat in Hindi cinema", although it referred to her part as "the only unique role in the film" and further noted, "An actor with proven talent for comedy, Chawla makes Pammi, her character, pathetic as well as feisty." The film earned worldwide.


title: Juhi Chawla

text: After a period of limited work in films, Chawla made a comeback in 2014 with "Gulaab Gang" opposite her once-archrival Madhuri Dixit. The film, in which Chawla and Dixit played ruthless political rivals, marked Chawla's role as an antagonist. Her portrayal of Sumitra Devi, a shrewd and conniving politician, was widely appreciated by critics. Shubhra Gupta of "The Financial Times" described her character as "the sort of politician that men have played for ever: hungry for power, will stop at nothing, not even murder and mayhem. She rules with an iron fist and a sneer." "Hindustan Times" wrote, "An effective hero needs a larger-than-life villain. In this case, it is Juhi Chawla who marries her sister to a rapist and apparently killed her husband to get political power. Like most corrupt politicians we see onscreen, she is an opportunist who lusts for power. It speaks well about her acting prowess that we come to hate the otherwise effervescent Juhi in this film." Anupama Chopra wrote, "Her perverse wickedness is the best part of the film", but called it a "a one-note character". Rajeev Masand called her "terrific" in the part and concluded a scathing review of the film asserting, "if you must watch this film, watch it for Juhi Chawla's inspired performance." She received a second Filmfare nomination for Best Supporting Actress. The same year she also appeared with Helen Mirren and Om Puri in a guest role in the Steven Spielberg-produced Hollywood film "The Hundred Foot Journey".


title: Juhi Chawla

text: In 2016, she starred in the woman-centric drama "Chalk n Duster" with Shabana Azmi. The film received mixed reviews from critics and Chawla's performance was well-received. In a critical review for "The Hindu", Namrata Joshi noted "Azmi and Chawla who, with their dignified presence and easy camaraderie stop you from heading to the exit door." Rohit Vats of "Hindustan Times" liked the film for its "well told ethics versus greed story" and mentioned Chawla's heartwarming presence. In 2017, she played an Indian defence minister in the Alt Balaji web series "The Test Case". She starred in the web series "Hush Hush""," which released on Amazon Prime Video on 22 September 2022


title: Juhi Chawla

text: In 1998, Chawla participated in a concert tour entitled "Awesome Foursome" alongside Shah Rukh Khan, Kajol, and Akshay Kumar across the United Kingdom, Canada and the United States.


title: Juhi Chawla

text: In 2009, Chawla featured as a talent judge, for the third season of Sony Entertainment Television India's dance reality show, "Jhalak Dikhhla Jaa" alongside Saroj Khan and Vaibhavi Merchant. In 2011, she hosted Colors's kid's chat-show Badmaash Company- Ek Shararat Hone Ko Hai.


title: Juhi Chawla

text: In 2008, Chawla, in partnership with Shah Rukh Khan and her husband Jay Mehta, acquired ownership rights for the franchise representing Kolkata in the Twenty20 cricket tournament Indian Premier League (IPL) for , and named the team Kolkata Knight Riders (KKR). The team won in 2012 and repeated the feat in 2014.


title: Juhi Chawla

text: Delhi High Court imposed a ₹20 lakh fine on Chawla after it found a lawsuit filed by Chawla against the setting up of 5G wireless networks to be 'frivolous'. The fine was later reduced to ₹2 lakh.


title: Juhi Chawla

text: Juhi Chawla married industrialist Jay Mehta in 1995. The couple has two children. In an interview Juhi revealed that her daughter Jhanvi wants to be a writer, instead of joining films.


title: Juhi Chawla

text: Her brother Bobby Chawla was the CEO of Red Chillies Entertainment. He suffered a massive stroke in 2010 after a dinner party. After being in coma for about four years, he died on 9 March 2014. Her sister, Sonia, died of cancer on 30 October 2012.


title: Juhi Chawla

text: Chawla was one of the leading actresses in the 1990s. As an actor, throughout most of her early career, she was particularly recognised for her comic timing and vivacious on-screen persona.


title: Juhi Chawla

text: Despite her success, Chawla has faced periods of commercial decline. Asked about some of the commercial flunctuations in her career, Chawla attributed them to wrong choices. Following the birth of her daughter and amidst the poor box-office performance of Chawla's work in the early 2000s, Chawla took a short break from acting in 2001 and spoke of her intention to come back with more serious roles. Eventually she felt her new choices had given her a new identity and constant interest.


title: Juhi Chawla

text: Several outlets noted her transition to serious cinema. Chawla said that with films like "3 Deewarein" and "My Brother Nikhil" she received satisfaction as an actor.


title: Three-body problem

text: In physics and classical mechanics, the three-body problem is the problem of taking the initial positions and velocities (or momenta) of three point masses and solving for their subsequent motion according to Newton's laws of motion and Newton's law of universal gravitation. The three-body problem is a special case of the -body problem. Unlike two-body problems, no general closed-form solution exists, as the resulting dynamical system is chaotic for most initial conditions, and numerical methods are generally required.


title: Three-body problem

text: Historically, the first specific three-body problem to receive extended study was the one involving the Moon, Earth, and the Sun. In an extended modern sense, a three-body problem is any problem in classical mechanics or quantum mechanics that models the motion of three particles.


title: Three-body problem

text: The mathematical statement of the three-body problem can be given in terms of the Newtonian equations of motion for vector positions formula_1 of three gravitationally interacting bodies with masses formula_2:


title: Three-body problem

text: In the "restricted three-body problem", a body of negligible mass (the "planetoid") moves under the influence of two massive bodies. Having negligible mass, the force that the planetoid exerts on the two massive bodies may be neglected, and the system can be analysed and can therefore be described in terms of a two-body motion. Usually this two-body motion is taken to consist of circular orbits around the center of mass, and the planetoid is assumed to move in the plane defined by the circular orbits.


title: Three-body problem

text: The restricted three-body problem is easier to analyze theoretically than the full problem. It is of practical interest as well since it accurately describes many real-world problems, the most important example being the Earth–Moon–Sun system. For these reasons, it has occupied an important role in the historical development of the three-body problem.


title: Three-body problem

text: Mathematically, the problem is stated as follows. Let formula_5 be the masses of the two massive bodies, with (planar) coordinates formula_6 and formula_7, and let formula_8 be the coordinates of the planetoid. For simplicity, choose units such that the distance between the two massive bodies, as well as the gravitational constant, are both equal to formula_9. Then, the motion of the planetoid is given by


title: Three-body problem

text: where formula_11. In this form the equations of motion carry an explicit time dependence through the coordinates formula_12. However, this time dependence can be removed through a transformation to a rotating reference frame, which simplifies any subsequent analysis.


title: Three-body problem

text: There is no general closed-form solution to the three-body problem, meaning there is no general solution that can be expressed in terms of a finite number of standard mathematical operations. Moreover, the motion of three bodies is generally non-repeating, except in special cases.


title: Three-body problem

text: However, in 1912 the Finnish mathematician Karl Fritiof Sundman proved that there exists an analytic solution to the three-body problem in the form of a power series in terms of powers of . This series converges for all real , except for initial conditions corresponding to zero angular momentum. In practice, the latter restriction is insignificant since initial conditions with zero angular momentum are rare, having Lebesgue measure zero.


title: Three-body problem

text: An important issue in proving this result is the fact that the radius of convergence for this series is determined by the distance to the nearest singularity. Therefore, it is necessary to study the possible singularities of the three-body problems. As will be briefly discussed below, the only singularities in the three-body problem are binary collisions (collisions between two particles at an instant) and triple collisions (collisions between three particles at an instant).


title: Three-body problem

text: Collisions, whether binary or triple (in fact, any number), are somewhat improbable, since it has been shown that they correspond to a set of initial conditions of measure zero. However, there is no criterion known to be put on the initial state in order to avoid collisions for the corresponding solution. So Sundman's strategy consisted of the following steps:


title: Three-body problem

text: The corresponding series, however, converges very slowly. That is, obtaining a value of meaningful precision requires so many terms that this solution is of little practical use. Indeed, in 1930, David Beloriszky calculated that if Sundman's series were to be used for astronomical observations, then the computations would involve at least 10 terms.


title: Three-body problem

text: In 1767, Leonhard Euler found three families of periodic solutions in which the three masses are collinear at each instant. See Euler's three-body problem.


title: Three-body problem

text: In 1772, Lagrange found a family of solutions in which the three masses form an equilateral triangle at each instant. Together with Euler's collinear solutions, these solutions form the central configurations for the three-body problem. These solutions are valid for any mass ratios, and the masses move on Keplerian ellipses. These four families are the only known solutions for which there are explicit analytic formulae. In the special case of the circular restricted three-body problem, these solutions, viewed in a frame rotating with the primaries, become points which are referred to as L, L, L, L, and L, and called Lagrangian points, with L and L being symmetric instances of Lagrange's solution.


title: Three-body problem

text: In work summarized in 1892–1899, Henri Poincaré established the existence of an infinite number of periodic solutions to the restricted three-body problem, together with techniques for continuing these solutions into the general three-body problem.


title: Three-body problem

text: In 1893, Meissel stated what is now called the Pythagorean three-body problem: three masses in the ratio 3:4:5 are placed at rest at the vertices of a 3:4:5 right triangle. Burrau further investigated this problem in 1913. In 1967 Victor Szebehely and C. Frederick Peters established eventual escape for this problem using numerical integration, while at the same time finding a nearby periodic solution.


title: Three-body problem

text: In the 1970s, Michel Hénon and Roger A. Broucke each found a set of solutions that form part of the same family of solutions: the Broucke–Henon–Hadjidemetriou family. In this family the three objects all have the same mass and can exhibit both retrograde and direct forms. In some of Broucke's solutions two of the bodies follow the same path.


title: Three-body problem

text: In 1993, a zero angular momentum solution with three equal masses moving around a figure-eight shape was discovered numerically by physicist Cris Moore at the Santa Fe Institute. Its formal existence was later proved in 2000 by mathematicians Alain Chenciner and Richard Montgomery. The solution has been shown numerically to be stable for small perturbations of the mass and orbital parameters, which makes it possible that such orbits could be observed in the physical universe. However, it has been argued that this occurrence is unlikely since the domain of stability is small. For instance, the probability of a binary–binary scattering event resulting in a figure-8 orbit has been estimated to be a small fraction of 1%.


title: Three-body problem

text: In 2013, physicists Milovan Šuvakov and Veljko Dmitrašinović at the Institute of Physics in Belgrade discovered 13 new families of solutions for the equal-mass zero-angular-momentum three-body problem.


title: Three-body problem

text: In 2015, physicist Ana Hudomal discovered 14 new families of solutions for the equal-mass zero-angular-momentum three-body problem.


title: Three-body problem

text: In 2017, researchers Xiaoming Li and Shijun Liao found 669 new periodic orbits of the equal-mass zero-angular-momentum three-body problem. This was followed in 2018 by an additional 1223 new solutions for a zero-angular-momentum system of unequal masses.


title: Three-body problem

text: In 2018, Li and Liao reported 234 solutions to the unequal-mass "free-fall" three body problem. The free fall formulation of the three body problem starts with all three bodies at rest. Because of this, the masses in a free-fall configuration do not orbit in a closed "loop", but travel forwards and backwards along an open "track".


title: Three-body problem

text: Using a computer, the problem may be solved to arbitrarily high precision using numerical integration although high precision requires a large amount of CPU time. There have been attempts of creating computer programs that numerically solve the three-body problem (and by extension, the n-body problem) involving both electromagnetic and gravitational interactions, and incorporating modern theories of physics such as special relativity. In addition, using the theory of random walks, the probability of different outcomes may be computed.


title: Three-body problem

text: The gravitational problem of three bodies in its traditional sense dates in substance from 1687, when Isaac Newton published his "Philosophiæ Naturalis Principia Mathematica," when Newton was trying to figure out if any long term stability is possible, especially the system of our Earth, the Moon, and the Sun. He was guided under the major Renaissance astronomers Nicolaus Copernicus, Tycho Brahe and Johannes Kepler to the beginning of the gravitational three-body problem. In Proposition 66 of Book 1 of the "Principia", and its 22 Corollaries, Newton took the first steps in the definition and study of the problem of the movements of three massive bodies subject to their mutually perturbing gravitational attractions. In Propositions 25 to 35 of Book 3, Newton also took the first steps in applying his results of Proposition 66 to the lunar theory, the motion of the Moon under the gravitational influence of Earth and the Sun. Later, this problem was also applied to other planets' interactions with the Earth and the Sun.


title: Three-body problem

text: The physical problem was firstly addressed by Amerigo Vespucci and subsequently by Galileo Galilei, as well as Simon Stevin, but they did not realize what they contributed. Though Galileo determined that the speed of fall of all bodies changes uniformly and in the same way, he did not apply it to planetary motions. Whereas in 1499, Vespucci used knowledge of the position of the Moon to determine his position in Brazil. It became of technical importance in the 1720s, as an accurate solution would be applicable to navigation, specifically for the determination of longitude at sea, solved in practice by John Harrison's invention of the marine chronometer. However the accuracy of the lunar theory was low, due to the perturbing effect of the Sun and planets on the motion of the Moon around Earth.


title: Three-body problem

text: Jean le Rond d'Alembert and Alexis Clairaut, who developed a longstanding rivalry, both attempted to analyze the problem in some degree of generality; they submitted their competing first analyses to the Académie Royale des Sciences in 1747. It was in connection with their research, in Paris during the 1740s, that the name "three-body problem" () began to be commonly used. An account published in 1761 by Jean le Rond d'Alembert indicates that the name was first used in 1747.


title: Three-body problem

text: From the end of the 19th century to early 20th century, the approach to solve the three-body problem with the usage of short-range attractive two-body forces was developed by scientists, which offered P.F. Bedaque, H.-W. Hammer and U. van Kolck an idea to renormalize the short-range three-body problem, providing scientists a rare example of a renormalization group limit cycle at the beginning of the 21st century. George William Hill worked on the restricted problem in the late 19th century with an application of motion of Venus and Mercury.


title: Three-body problem

text: At the beginning of the 20th century, Karl Sundman approached the problem mathematically and systematically by providing a function theoretical proof to the problem valid for all values of time. It was the first time scientists theoretically solved three-body problem. However, because there was not enough qualitative solution of this system, and it was too slow for scientists to practically apply it, this solution still left some issues unresolved. In the 1970s, implication to three-body from two-body forces has been discovered by V. Efimov which was named as Efimov Effect.


title: Three-body problem

text: In 2017, Shijun Liao and Xiaoming Li applied a new strategy of numerical simulation for chaotic systems called the clean numerical simulation (CNS), with the use of a national supercomputer, to successfully gain 695 families of periodic solutions of the three-body system with equal mass.


title: Three-body problem

text: In 2019, Breen et al. announced a fast neural network solver for the three-body problem, trained using a numerical integrator.


title: Three-body problem

text: The term "three-body problem" is sometimes used in the more general sense to refer to any physical problem involving the interaction of three bodies.


title: Three-body problem

text: A quantum-mechanical analogue of the gravitational three-body problem in classical mechanics is the helium atom,


title: Three-body problem

text: in which a helium nucleus and two electrons interact according to the inverse-square Coulomb interaction. Like the


title: Three-body problem

text: In both classical and quantum mechanics, however, there exist nontrivial interaction laws besides the inverse-square force which


title: Three-body problem

text: do lead to exact analytic three-body solutions. One such model consists of a combination of harmonic attraction and a repulsive inverse-cube force. This model is considered nontrivial since it is associated with a set of nonlinear differential equations containing singularities (compared with, e.g., harmonic interactions alone, which lead to an easily solved system of linear differential equations). In these two respects it is analogous to (insoluble) models having Coulomb interactions, and as a result has been suggested as a tool for intuitively understanding physical systems like the helium atom.


title: Three-body problem

text: The gravitational three-body problem has also been studied using general relativity. Physically, a relativistic treatment becomes necessary in systems with very strong gravitational fields, such as near the event horizon of a black hole. However, the relativistic problem is considerably more difficult than in Newtonian mechanics, and sophisticated numerical techniques are required.


title: Three-body problem

text: Even the full two-body problem (i.e. for arbitrary ratio of masses) does not have a rigorous analytic solution in general relativity.


title: Three-body problem

text: The three-body problem is a special case of the -body problem, which describes how objects move under one of the physical forces, such as gravity. These problems have a global analytical solution in the form of a convergent power series, as was proven by Karl F. Sundman for and by Qiudong Wang for (see -body problem for details). However, the Sundman and Wang series converge so slowly that they are useless for practical purposes; therefore, it is currently necessary to approximate solutions by numerical analysis in the form of numerical integration or, for some cases, classical trigonometric series approximations (see -body simulation). Atomic systems, e.g. atoms, ions, and molecules, can be treated in terms of the quantum -body problem. Among classical physical systems, the -body problem usually refers to a galaxy or to a cluster of galaxies; planetary systems, such as stars, planets, and their satellites, can also be treated as -body systems. Some applications are conveniently treated by perturbation theory, in which the system is considered as a two-body problem plus additional forces causing deviations from a hypothetical unperturbed two-body trajectory.


title: Three-body problem

text: In the classic 1951 science-fiction film "The Day the Earth Stood Still", the alien Klaatu, using the pseudonym Mr. Carpenter, makes some annotations to equations on Prof. Barnhardt's blackboard. Those equations are an accurate description of a particular form of the three-body problem.


title: Three-body problem

text: The first volume of Chinese author Liu Cixin's "Remembrance of Earth's Past" trilogy is titled "The Three-Body Problem" and features the three-body problem as a central plot device.


title: Persepolis

text: Persepolis (; ; ) was the ceremonial capital of the Achaemenid Empire (). It is situated in the plains of Marvdasht, encircled by southern Zagros mountains of the Iranian plateau. Modern day Shiraz is situated southwest of the ruins of Persepolis. The earliest remains of Persepolis date back to 515 BC. It exemplifies the Achaemenid style of architecture. UNESCO declared the ruins of Persepolis a World Heritage Site in 1979.


title: Persepolis

text: The complex is raised high on a walled platform, with five "palaces" or halls of varying size, and grand entrances. The function of Persepolis remains quite unclear. It was not one of the largest cities in Persia, let alone the rest of the empire, but appears to have been a grand ceremonial complex that was only occupied seasonally; it is still not entirely clear where the king's private quarters actually were. Until recent challenges, most archaeologists held that it was especially used for celebrating Nowruz, the Persian New Year, held at the spring equinox, and still an important annual festivity in modern Iran. The Iranian nobility and the tributary parts of the empire came to present gifts to the king, as represented in the stairway reliefs.


title: Persepolis

text: It is also unclear what permanent structures there were outside the palace complex; it may be better to think of Persepolis as just that complex rather than a "city" in the normal sense.


title: Persepolis

text: The complex was taken by the army of Alexander the Great in 330 BC, and soon after the wooden parts were completely destroyed by fire, very likely deliberately.


title: Persepolis

text: "Persepolis" is derived from the Greek , a compound of () and (), together meaning "the Persian city" or "the city of the Persians". To the ancient Persians, the city was known as (), which is also the word for the region of Persia.


title: Persepolis

text: An inscription left in 311 AD by Sasanian prince Shapur Sakanshah, the son of Hormizd II, refers to the site as , meaning "Hundred Pillars". Because medieval Persians attributed the site to Jamshid, a king from Iranian mythology, it has been referred to as (, ; ), literally meaning "Throne of Jamshid". Another name given to the site in the medieval period was (, "Forty Minarets"), transcribed as in De Silva Figueroa and as Chilminar in early English sources.


title: Persepolis

text: The site includes a terrace, partly artificially constructed and partly cut out of a mountain, with its east side leaning on Rahmat Mountain. The other three sides are formed by retaining walls, which vary in height with the slope of the ground. Rising from on the west side was a double stair. From there, it gently slopes to the top. To create the level terrace, depressions were filled with soil and heavy rocks, which were joined together with metal clips.