Emperor An emperor ( through Old French " empereor " from Latin " imperator " ) is a ( male ) monarch , usually the sovereign ruler of an empire or another type of imperial realm . Empress , the female equivalent , may indicate an emperor ' s wife ( " empress consort " ) , mother ( " empress dowager " ) , or a woman who rules in her own right ( " empress regnant " ) . Emperors are generally recognized to be of a higher honor and rank than kings . The Emperor of Japan is the only remaining reigning monarch in the world reigning under the title of " Emperor " . Distinction from other monarchs . Both kings and emperors are monarchs . Within the European context , " emperor " and " empress " are considered the higher monarchical titles . However , monarchs heading empires have not always used the title — the British sovereign did not assume the title until the incorporation of India into the British Empire , and even then used it only in a limited context . Emperors were once given precedence over kings , but under the pope , in international diplomatic relations ; currently , precedence is decided by the length a head of state is continuously in office . Outside the European context , " emperor " is a translation given to holders of titles who are accorded the same precedence as European emperors in diplomatic terms . In reciprocity , these rulers may accredit equal titles in their native languages to their European peers . Through centuries of international convention , this has become the dominant rule to identifying an emperor in the modern era . Some empires , such as the Holy Roman Empire and the Russian Empire , derived their office from the authority of the Roman Emperors ( " translatio imperii " ) . The title was a conscious attempt by monarchs to link themselves to the institutions and traditions of the Romans as part of state ideology . Similarly , many republics have named a legislative chamber after the Roman Senate . Historians have liberally used " emperor " and , especially so , " empire " anachronistically and out of its Roman and European context to describe any large state and its ruler in the past and present ; sometimes even to refer to non - monarchically ruled states and their spheres of influence : such examples include the " Athenian Empire " of the late 5th century BC , the " Angevin Empire " of the Plantagenets , or the Soviet and American " empires " of the Cold War era . " Empire " became identified with vast territorial holdings rather than the title of its ruler by the mid - 18th century . Roman tradition . The title was first used as an honorific for a military leader in ancient Rome . In the Roman tradition a large variety in the meaning and importance of the imperial form of monarchy developed : in " intention " it was always the highest office , but it could as well fall down to a redundant title for nobility that had never been near to the " Empire " they were supposed to be reigning . Also the " name " of the position split in several branches of Western tradition , see below . The importance and meaning of coronation ceremonies and regalia also varied within the tradition : for instance Holy Roman Emperors could only be crowned emperor by the pope , which meant the coronation ceremony usually took place in Rome , often several years after these emperors had ascended to the throne ( as " king " ) in their home country . The first Latin Emperors of Constantinople on the other hand had to be present in the newly conquered capital of their empire , because that was the only place where they could be granted to become emperor . Early Roman Emperors avoided any type of ceremony or regalia different from what was already usual for republican offices in the Roman Republic : the most intrusive change had been changing the color of their robe to purple . Later new symbols of worldly and / or spiritual power , like the orb became an essential part of the imperial accessories . Rules for indicating successors also varied : there was a tendency towards " male " " inheritance " of the supreme office , but as well election by noblemen , as ruling empresses ( for empires not too strictly under salic law ) are known . Ruling monarchs could additionally steer the succession by adoption , as often occurred in the two first centuries of Imperial Rome . Of course , intrigue , murder and military force could also mingle in for appointing successors ; the Roman imperial tradition made no exception to other monarchical traditions in this respect . Probably the epoch best known for this part of the imperial tradition is Rome ' s third century rule . Ancient Roman empire and Byzantine emperors . Classical Antiquity . When Republican Rome turned into a " de facto " monarchy in the second half of the 1st century BC , at first there was no name for the title of the new type of monarch . Ancient Romans abhorred the name Rex ( " king " ) , and it was critical to the political order to maintain the forms and pretenses of republican rule . Julius Caesar had been Dictator , an acknowledged and traditional office in Republican Rome . Caesar was not the first to hold it , but following his assassination the term was abhorred in Rome . Augustus , considered the first Roman Emperor , established his by collecting on himself offices , titles , and honours of Republican Rome that had traditionally been distributed to different people , concentrating what had been distributed power in one man . One of these offices was " princeps senatus " , ( " first man of the Senate " ) and became shortened into Augustus ' chief honorific , " Princeps " ( usually translated as " first citizen " ) from which the modern English word and title prince is descended . The first period of the Roman Empire , from 27 BC - 284 AD , is called the " principate " for this reason . However , it was the informal descriptive of " Imperator " ( " commander " ) that became the title increasingly favored by his successors . Previously bestowed on high officials and military commanders who had " imperium " , Augustus reserved it exclusively to himself as the ultimate holder of all " imperium " . ( " Imperium " is Latin for the authority to command , one of a various types of authority delineated in Roman political thought . ) Beginning with Augustus , " Imperator " appeared in the title of all Roman monarchs through the extinction of the Empire in 1453 . After the reign of Augustus ' immediate successor Tiberius , being proclaimed " imperator " was transformed into the act of accession to the head of state . Other honorifics used by the Roman Emperors have also come to be synonyms for Emperor : After the turbulent Year of the four emperors in 69 , the Flavian Dynasty reigned for three decades . The succeeding Nervan - Antonian Dynasty , ruling for most of the 2nd century , stabilised the Empire . This epoch became known as the era of the " Five Good Emperors " , and was followed by the short - lived Severan Dynasty . During the Crisis of the 3rd century , Barracks Emperor s succeeded one another at short intervals . Three short lived secessionist attempts had their own emperors : the Gallic Empire , the Britannic Empire , and the Palmyrene Empire though the latter used " rex " more regularly . The Principate ( 27 BC - 284 AD ) period was succeeded by what is known as the Dominate ( 284 AD - 527 AD ) , during which Emperor Diocletian tried to put the Empire on a more formal footing . Diocletion sought to address the challenges of the Empire ' s now vast geography and the instability caused by the informality of succession by the creation of co - emperors and junior emperors . At one point , there were as many as five sharers of the " imperium " ( see : Tetrarchy ) . In 325 AD Constantine I abolished the system and restored single emperor rule , but following the death of Theodosius in 395 AD , the empire returned to the system of co - emperors , each with primary authority for half the empire . The areas administered from Rome are referred to by historians the Western Roman Empire and those under the immediate authority of Constantinople called the Eastern Roman Empire or ( after the Battle of Yarmouk in 636 AD ) the Later Roman or Byzantine Empire . The subdivisions and co - emperor system were formally abolished by Emperor Zeno in 480 AD following the death of Julius Nepos last Western Emperor and the ascension of Odoacer as the " de facto " King of Italy in 476 AD . Byzantine period . Prior to the 4th Crusade . Historians generally refer to the continuing Roman Empire in the east as the Byzantine Empire after Byzantium , the original name of the town that Constantine I would elevate to the Imperial capital as New Rome in AD 330 . ( The city is more commonly called Constantinople and is today named Istanbul ) . Although the empire was again subdivided and a co - emperor sent to Italy at the end of the fourth century , the office became unitary again only 95 years later at the request of the Roman Senate and following the death of Julius Nepos , last Western Emperor . This change was a recognition of the reality that little remained of Imperial authority in the areas that had been the Western Empire , with even Rome and Italy itself now ruled by the essentially autonomous Odoacer . The Byzantine Emperors completed the transition from the idea of the Emperor as a semi - republican official to the Emperor as an absolute monarch . Of particular note was the translation of the Latin " Imperator " into the Greek " Basileus " , after Emperor Heraclius changed the official language of the empire from Latin to Greek in AD 620 . Basileus , a title which had long been used for Alexander the Great was already in common usage as the Greek word for the Roman emperor , but its definition and sense was " King " in Greek , essentially equivalent with the Latin " Rex " . Byzantine period emperors also used the Greek word " autokrator " , meaning " one who rules himself " , or " monarch " , which was traditionally used by Greek writers to translate the Latin " dictator " . Essentially , the Greek language did not incorporate the nuances of the Ancient Roman concepts that distinguished " imperium " from other forms of political power . In general usage , the Byzantine imperial title evolved from simply " emperor " ( " basileus " ) , to " emperor of the Romans " ( " basileus tōn Rōmaiōn " ) in the 9th century , to " emperor and autocrat of the Romans " ( " basileus kai autokratōr tōn Rōmaiōn " ) in the 10th . In fact , none of these ( and other ) additional epithets and titles had ever been completely discarded . One important distinction between the post Constantine I ( reigned AD 306 – 337 ) emperors and their pagan predecessors was cesaropapism , the assertion that the Emperor ( or other head of state ) is also the head of the Church . Although this principle was held by all emperors after Constantine , it met with increasing resistance and ultimately rejection by bishops in the west after the effective end of Imperial power in there . This concept became a key element of the meaning of " emperor " in the Byzantine and Orthodox east , but went out of favor with in the west with the rise of Roman Catholicism . The Byzantine empire also produced three women who effectively governed the state : the Empress Irene and the Empresses Zoe and Theodora . Latin emperors . In 1204 Constantinople fell to the Venetians and the Franks in the Fourth Crusade . Following the tragedy of the horrific sacking of the city , the conquerors declared a new " Empire of Romania " , known to historians as the Latin Empire of Constantinople , installing Baldwin IX , Count of Flanders , as Emperor . However , Byzantine resistance to the new empire meant that it was in constant struggle to establish itself . Byzantine Emperor Michael VII Palaiologos succeeded in recapturing Constantinople in 1261 . The Principality of Achaea , a vassal state the empire had created in Morea ( Greece ) intermittently continued to recognize the authority of the crusader emperors for another half century . Pretenders to the title continued among the European nobility until circa 1383 . After the 4th Crusade . With Constantinople occupied , claimants to the imperial succession styled themselves as emperor in the chief centers of resistance : The Lackarid dynasty in the Empire of Nicaea , the Komnenid dynasty in the Empire of Trebizond and the Doukid dynasty in the Despotate of Epirus . In 1248 AD , the Epirus recognized the Nicaean Emperors , who then recaptured Constantinople in 1261 AD . The Trebizond emperor formally submitted in Constantinople in 1281 AD , but frequently flouted convention by styling themselves emperor back in Trebizond thereafter . Ottoman Empire . Ottoman rulers held several titles denoting their Imperial status . These included : Sultan , Khan , Sovereign of the Imperial House of Osman , Sultan of Sultans , Khan of Khans , Commander of the Faithful and Successor of the Prophet of the Lord of the Universe , Protector of the Holy Cities of Mecca , Medina and Jerusalem , Emperor of The Three Cities of Constantinople , Adrianopole and Bursa as well as many other cities and countries . After the Ottoman capture of Constantinople in 1453 , the Ottoman sultans began to style themselves Kaysar - i Rum ( Emperor of the Romans ) as they asserted themselves to be the heirs to the Roman empire by right of conquest . The title was of such importance to them that it led them to eliminate the various Byzantine successor states - and therefore rival claimants - over the next eight years . Holy Roman Empire . The " Roman " of the Emperor ' s title was a reflection of the " translatio imperii " ( " transfer of rule " ) principle that regarded the Holy Roman Emperors as the inheritors of the title of Emperor of the Western Roman Empire , a title left unclaimed in the West after the death of Julius Nepos in 480 . From the time of Otto the Great onward , much of the former Carolingian kingdom of Eastern Francia became the Holy Roman Empire . The various ( German ) kings such as the king of Bavaria , Saxony , Prussia e . g . elected one of their peers as " " Kaiser " of the Germans before crowned by the pope " . The Emperor could also pursue the election of his heir ( usually a son ) as King , who would then succeed him after his death . This junior King then bore the title " King of the Romans " . Although technically already ruling , after the election he would be crowned as emperor by the Pope . The last emperor to be crowned by the pope was Charles V ; all emperors after him were technically " emperors - elect " , but were universally referred to as " Emperor " . Austrian Empire . The first Austrian Emperor was the last Holy Roman Emperor Francis II . In the face of aggressions by Napoleon , Francis feared for the future of the Holy Roman Empire . He wished to maintain his and his family ' s Imperial status in the event that the Holy Roman Empire should be dissolved , as it indeed was in 1806 when an Austrian - led army suffered a humiliating defeat at the Battle of Austerlitz . After which , the victorious Napoleon proceeded to dismantle the old " Reich " by severing a good portion from the empire and turning it into a separate Confederation of the Rhine . With the size of his imperial realm significantly reduced , Francis II , " Holy Roman Emperor " became Francis I , " Emperor of Austria " . The new imperial title may have sounded less prestigious than the old one , but Francis ' dynasty continued to rule from Austria and a Habsburg monarch was still an emperor ( " Kaiser " ) , and not just merely a king ( " König " ) , in name . The title lasted just a little over one century until 1918 , but it was never clear what territory constituted the " Empire of Austria " . When Francis took the title in 1804 , the Habsburg lands as a whole were dubbed the " Kaisertum Österreich " . " Kaisertum " might literally be translated as " emperordom " ( on analogy with " kingdom " ) or " emperor - ship " ; the term denotes specifically " the territory ruled by an emperor " , and is thus somewhat more general than Reich , which in 1804 carried connotations of universal rule . Austria proper ( as opposed to the complex of Habsburg lands as a whole ) had been an Archduchy since the 15th century , and most of the other territories of the Empire had their own institutions and territorial history , although there were some attempts at centralization , especially during the reign of Marie Therese and her son Joseph II and then finalized in the early 19th century . When Hungary was given self - government in 1867 , the non - Hungarian portions were called the Empire of Austria and were officially known as the " Kingdoms and Lands Represented in the Imperial Council ( " Reichsrat " ) " . The title of Emperor of Austria and the associated Empire were both abolished at the end of the First World War in 1918 , when German Austria became a republic and the other kingdoms and lands represented in the Imperial Council established their independence or adhesion to other states . Emperors of Eastern Europe . Byzantium ' s close cultural and political interaction with its Balkan neighbors Bulgaria and Serbia , and with Russia ( Kievan Rus ' , then Muscovy ) led to the adoption of Byzantine imperial traditions in all of these countries . Bulgaria . In 913 , Simeon I of Bulgaria was crowned Emperor ( Tsar ) by the Patriarch of Constantinople and imperial regent Nicholas Mystikos outside of the Byzantine capital . In its final simplified form , the title read " Emperor and Autocrat of all Bulgarians and Romans " ( " Tsar i samodarzhets na vsichki balgari i gartsi " in the modern vernacular ) . The Roman component in the Bulgarian imperial title indicated both rulership over Greek speakers and the derivation of the imperial tradition from the Romans . Byzantine recognition of Simeon ' s imperial title was revoked by the succeeding Byzantine government . The decade 914 – 924 was spent in destructive warfare between Byzantium and Bulgaria over this and other matters of conflict . The Bulgarian monarch , who had further irritated his Byzantine counterpart by claiming the title " Emperor of the Romans " ( " basileus tōn Rōmaiōn " ) , was eventually recognized , as " Emperor of the Bulgarians " ( " basileus tōn Boulgarōn " ) by the Byzantine Emperor Romanos I Lakapenos in 924 . Byzantine recognition of the imperial dignity of the Bulgarian monarch and the patriarchal dignity of the Bulgarian patriarch was again confirmed at the conclusion of permanent peace and a Bulgarian - Byzantine dynastic marriage in 927 . In the meantime , the Bulgarian imperial title may have been also confirmed by the pope . The Bulgarian imperial title " tsar " was adopted by all Bulgarian monarchs up to the fall of Bulgaria under Ottoman rule . 14th - century Bulgarian literary compositions clearly denote the Bulgarian capital ( Tarnovo ) as a successor of Rome and Constantinople , in effect , the " Third Rome " . It should be noted that after Bulgaria obtained full independence from the Ottoman Empire in 1908 , its monarch , who was previously styled " Knyaz " , i . e . , Prince , took the traditional title of " Tsar " which in Bulgarian means King and was recognized internationally as such . Serbia . In 1345 , the Serbian King Stefan Uroš IV Dušan proclaimed himself Emperor ( Tsar ) and was crowned as such at Skopje on Easter 1346 by the newly created Patriarch of Serbia , and by the Patriarch of Bulgaria and the autocephalous Archbishop of Ohrid . His imperial title was recognized by Bulgaria and various other neighbors and trading partners but not by the Byzantine Empire . In its final simplified form , the Serbian imperial title read " Emperor of Serbs and Greeks " ( " цар Срба и Грка " in modern Serbian ) . It was only employed by Stefan Uroš IV Dušan and his son Stefan Uroš V in Serbia ( until his death in 1371 ) , after which it became extinct . A half - brother of Dušan , Simeon Uroš , and then his son Jovan Uroš , claimed the same title , until the latter ' s abdication in 1373 , while ruling as dynasts in Thessaly . The " Greek " component in the Serbian imperial title indicates both rulership over Greeks and the derivation of the imperial tradition from the Romans . Russia . In 1472 , the niece of the last Byzantine emperor , Sophia Palaiologina , married Ivan III , grand prince of Moscow , who began championing the idea of Russia being the successor to the Byzantine Empire . This idea was represented more emphatically in the composition the monk Filofej addressed to their son Vasili III . After ending Muscovy ' s dependence on its Mongol overlords in 1480 , Ivan III began the usage of the titles Tsar and Autocrat ( " samoderzhets " ) . His insistence on recognition as such by the emperor of the Holy Roman Empire since 1489 resulted in the granting of this recognition in 1514 by Emperor Maximilian I to Vasili III . His son Ivan IV emphatically crowned himself Tsar ( Tsar ) on 16 January 1547 . The word Tsar derives from Latin Caesar , but this title was used in Russia as equivalent to King ; the error occurred when medieval Russian clerics referred to the biblical Jewish kings with the same title that was used to designate Roman and Byzantine rulers - Caesar . On 31 October 1721 , Peter I was proclaimed Emperor by the Senate - the title used was Latin " " Imperator " " , which is a westernizing form equivalent to the traditional Slavic title " " Tsar " " . He based his claim partially upon a letter discovered in 1717 written in 1514 from Maximilian I to Vasili III , in which the Holy Roman Emperor used the term in referring to Vasili . The title has not been used in Russia since the abdication of Emperor Nicholas II on 15 March 1917 . Imperial Russia produced four reigning Empresses , all in the eighteenth century . Emperors in Western Europe . France . The kings of the " Ancien Régime " and the July Monarchy used the title " Empereur de France " in diplomatic correspondence and treaties with the Ottoman emperor from at least 1673 onwards . The Ottomans insisted on this elevated style while refusing to recognize the Holy Roman Emperors or the Russian tsars because of their rival claims of the Roman crown . In short , it was an indirect insult by the Ottomans to the HRE and the Russians . The French kings also used it for Morocco ( 1682 ) and Persia ( 1715 ) . First French Empire . Napoleon Bonaparte , who was already First Consul of the French Republic ( " Premier Consul de la République française " ) for life , declared himself Emperor of the French ( " Empereur des Français " ) on 18 May 1804 , thus creating the Empire of the French ( " Empire des Français " ) . Napoleon relinquished the title of Emperor of the French on 6 April and again on 11 April 1814 . Napoleon ' s infant son , Napoleon II , was recognized by the Council of Peers , as Emperor from the moment of his father ' s abdication , and therefore reigned ( as opposed to ruled ) as Emperor for fifteen days , 22 June to 7 July 1815 . Elba . Since 3 May 1814 , the Sovereign Principality of Elba was created a miniature non - hereditary Monarchy under the exiled French Emperor Napoleon I . Napoleon I was allowed , by the treaty of Fontainebleau with ( 27 April ) , to enjoy , for life , the imperial title . The islands were " not " restyled an empire . On 26 February 1815 , Napoleon abandoned Elba for France , reviving the French Empire for a Hundred Days ; the Allies declared an end to Napoleon ' s sovereignty over Elba on 25 March 1815 , and on 31 March 1815 Elba was ceded to the restored Grand Duchy of Tuscany by the Congress of Vienna . After his final defeat , Napoleon was treated as a general by the British authorities during his second exile to Atlantic Isle of St . Helena . His title was a matter of dispute with the governor of St Helena , who insisted on addressing him as " General Bonaparte " , despite the " historical reality that he had been an emperor " and therefore retained the title . Second French Empire . Napoleon I ' s nephew , Napoleon III , resurrected the title of emperor on 2 December 1852 , after establishing the Second French Empire in a presidential coup , subsequently approved by a plebiscite . His reign was marked by large scale public works , the development of social policy , and the extension of France ' s influence throughout the world . During his reign , he also set about creating the Second Mexican Empire ( headed by his choice of Maximilian I of Mexico , a member of the House of Habsburg ) , to regain France ' s hold in the Americas and to achieve greatness for the ' Latin ' race . Napoleon III was deposed on 4 September 1870 , after France ' s defeat in the Franco - Prussian War . The Third Republic followed and after the death of his son Napoleon ( IV ) , in 1879 during the Zulu War , the Bonapartist movement split , and the Third Republic was to last until 1940 . Iberian Peninsula . The origin of the title " Imperator totius Hispaniae " ( Latin for " Emperor of All Spain " ) is murky . It was associated with the Leonese monarchy perhaps as far back as Alfonso the Great ( " r . " 866 - 910 ) . The last two kings of its Pérez Dynasty were called emperors in a contemporary source . King Sancho III of Navarre conquered Leon in 1034 and began using it . His son , Ferdinand I of Castile also took the title in 1039 . Ferdinand ' s son , Alfonso VI of León and Castile took the title in 1077 . It then passed to his son - in - law , Alfonso I of Aragon in 1109 . His stepson and Alfonso VI ' s grandson , Alfonso VII was the only one who actually had an imperial coronation in 1135 . The title was not exactly hereditary but self - proclaimed by those who had , wholly or partially , united the Christian northern part of the Iberian Peninsula , often at the expense of killing rival siblings . The popes and Holy Roman emperors protested at the usage of the imperial title as a usurpation of leadership in western Christendom . After Alfonso VII ' s death in 1157 , the title was abandoned , and the kings who used it are not commonly mentioned as having been " emperors " , in Spanish or other historiography . After the fall of the Byzantine Empire , the legitimate heir to the throne , Andreas Palaiologos , willed away his claim to Ferdinand and Isabella in 1503 . This claim seems to have been forgotten or abandoned quietly for the last 300 years . Britain . In the late 3rd century , by the end of the epoch of the " barracks emperors " in Rome , there were two Britannic Emperors , reigning for about a decade . After the end of Roman rule in Britain , the Imperator Cunedda forged the Kingdom of Gwynedd in northern Wales , but all his successors were titled kings and princes . England . There was no set title for the king of England before 1066 and monarchs chose to style themselves as they pleased . Imperial titles were used inconsistently beginning with Athelstan in 930 and ended with the Norman conquest of England . Empress Matilda ( 1102 – 1167 ) is the only British monarch commonly referred to as " emperor " or " empress " , but acquired her title through her marriage to Henry V , Holy Roman Emperor , and had little legitimacy as Queen of England . During the rule of Henry VIII an Act of Parliament declared that ' this realm of England is an Empire . . . governed by one Supreme Head and King having the dignity and royal estate of the imperial Crown of the same ' . Hence England and , by extension its modern successor state , the United Kingdom of Great Britain and Northern Ireland , is in fact an Empire ruled by a King endowed with the imperial dignity . However , this has not led to the creation of the " title " of Emperor in England or in the United Kingdom itself . United Kingdom . In 1801 , George III rejected the title of Emperor when offered . The only period when British monarchs held the title of " Emperor " in a dynastic succession started when the title Empress of India was created for Queen Victoria . The government led by Prime Minister Benjamin Disraeli , conferred the additional title upon her by an Act of Parliament , reputedly to assuage the monarch ' s irritation at being , as a mere Queen , notionally inferior to her own daughter ( Princess Victoria was the wife of the reigning German Emperor ) ; the Indian Imperial designation was also formally justified as the expression of Britain succeeding as paramount ruler of the subcontinent the former Mughal ' Padishah of Hind ' , using indirect rule through hundreds of princely state s formally under protection , not colonies , but accepting the British Sovereign as their suzerain . That title was relinquished by the last " Kaisar - i - Hind " George VI when India was granted independence on 15 August 1947 . Two decades earlier the Royal and Parliamentary Titles Act 1927 had stated that the United Kingdom and the dominions were " equal in status , in no way subordinate one to another in any aspect of their domestic or external affairs , though united by common allegiance to the Crown , and freely associated as members of the British Commonwealth of Nations " . Along with the Statute of Westminster , 1931 this changed the way the British parliamentary monarchy ruled the overseas dominions , moving from a colonial British Empire towards a new structure for the interaction between the Commonwealth Realms and the Crown . The last Empress of India was HM Queen Elizabeth , The Queen Mother . German Empire . Under the guise of idealism giving way to realism , German nationalism rapidly shifted from its liberal and democratic character in 1848 to Prussian prime minister Otto von Bismarck ' s authoritarian " Realpolitik " . Bismarck wanted to unify the rival German states to achieve his aim of a conservative , Prussian - dominated Germany . Three wars led to military successes and helped to convince German people to do this : the Second war of Schleswig against Denmark in 1864 , the Austro - Prussian War against Austria in 1866 , and the Franco - Prussian War against the Second French Empire in 1870 – 71 . During the Siege of Paris in 1871 , the North German Confederation , supported by its allies from southern Germany , formed the German Empire with the proclamation of the Prussian king Wilhelm I as German Emperor in the Hall of Mirrors at the Palace of Versailles , to the humiliation of the French , who ceased to resist only days later . After his death he was succeeded by his son Frederick III who was only emperor for 99 days . In the same year his son Wilhelm II became the third emperor within a year . He was the last German emperor . After the empire ' s defeat in World War I the empire ceased to exist . Post - colonial emperors modeled on Europe . Post - Columbian Americas . Brazil . When Napoleon I ordered the invasion of Portugal in 1807 because it refused to join the Continental System , the Portuguese Braganças moved their capital to Rio de Janeiro to avoid the fate of the Spanish Bourbons ( Napoleon I arrested them and made his brother Joseph king ) . When the French general Junot arrived in Lisbon , the Portuguese fleet had already left with all the local elite . In 1808 , under a British naval escort , the fleet arrived in Brazil . Later , in 1815 , the Portuguese Prince Regent ( since 1816 king D . João VI ) proclaimed the " United Kingdom of Portugal , Brazil and the Algarve " , as a union of three kingdoms , lifting Brazil from its colonial status . After the fall of Napoleon I and the Liberal revolution in Portugal , the Portuguese Royals returned to Europe ( 1820 ) . Prince Pedro of Bragança ( King D . João ' s older son ) stayed in South America acting as regent of the local kingdom , but , two years later in 1822 , he proclaimed himself D . Pedro I , first Emperor of Brazil . He did , however , recognize his father , D . João VI , as " Titular Emperor of Brazil " — a purely honorific title — until D . João VI ' s death in 1826 . The empire came to an end in 1889 , with the overthrow of Emperor D . Pedro II ( D . Pedro I ' s son and successor ) , when the Brazilian republic was proclaimed . Haiti . Haiti was declared an empire by its ruler , Jean - Jacques Dessalines , who made himself Jacques I , in 20 May 1805 . He was assassinated the next year . Haiti again became an empire from 1849 to 1859 under Faustin Soulouque . Mexico . In Mexico , the First Mexican Empire was the first of two empires created . After the declaration of independence on September 15 , 1821 , it was the intention of the Mexican parliament to establish a commonwealth whereby the King of Spain , Ferdinand VII , would also be Emperor of Mexico , but in which both countries were to be governed by separate laws and with their own legislative offices . Should the king refuse the position , the law provided for a member of the House of Bourbon to accede to the Mexican throne . Ferdinand VII , however , did not recognize the independence and said that Spain would not allow any other European prince to take the throne of Mexico . By request of Parliament , the president of the regency Agustín de Iturbide was proclaimed emperor of Mexico in 12 July 1822 as Agustín I . Agustín de Iturbide was the general who helped secure Mexican independence from Spanish rule , but was overthrown by the Plan of Casa Mata . In 1863 , the invading French , under Napoleon III ( see above ) , in alliance with Mexican conservatives and nobility , helped create the Second Mexican Empire , and invited Archduke Maximilian , of the House of Habsburg - Lorraine , younger brother of the Austrian Emperor Franz Josef I , to become emperor Maximilian I of Mexico . The childless Maximilian and his consort Empress Carlota of Mexico , daughter of Leopold I of Belgium , adopted Agustín ' s grandsons Agustin and Salvador as his heirs to bolster his claim to the throne of Mexico . Maximilian and Carlota made Chapultepec Castle their home , which has been the only palace in North America to house sovereigns . After the withdrawal of French protection in 1867 , Maximilian was captured and executed by the liberal forces of Benito Juárez . This empire led to French influence in the Mexican culture and also immigration from France , Belgium , and Switzerland to Mexico . Pre - Columbian traditions . The Aztec and Inca traditions are unrelated to one another . Both were conquered under the reign of King Charles I of Spain who was simultaneously emperor - elect of the Holy Roman Empire during the fall of the Aztecs and fully emperor during the fall of the Incas . Incidentally by being king of Spain , he was also Roman ( Byzantine ) emperor in pretence through Andreas Palaiologos . The translations of their titles were provided by the Spanish . Aztec Empire . The only pre - Columbian North American rulers to be commonly called emperors were the " Hueyi Tlatoani " of the Aztec Empire ( 1375 – 1521 ) . It was an elected monarchy chosen by the elite . Spanish conquistador Hernán Cortés slew Emperor Cuauhtémoc and installed puppet rulers who became vassals for Spain . Mexican Emperor Maximilian built his palace , Chapultepec Castle , over the ruins of an Aztec one . Inca Empire . The only pre - Columbian South American rulers to be commonly called emperors were the " Sapa Inca " of the Inca Empire ( 1438 – 1533 ) . Spanish conquistador Francisco Pizarro , conquered the Inca for Spain , killed Emperor Atahualpa , and installed puppets as well . Atahualpa may actually be considered a usurper as he had achieved power by killing his half - brother and he did not perform the required coronation with the imperial crown " mascaipacha " by the " Huillaq Uma " ( high priest ) . Persia . In Persia , from the time of Darius the Great , Persian rulers used the title " King of Kings " ( " Shahanshah " in modern Iranian ) since they had dominion over peoples from India to Greece . Alexander the Great probably crowned himself " shahanshah " after conquering Persia , bringing the phrase " basileus toon basileoon " to Greek . It is also known that Tigranes the Great , king of Armenia , was named as the king of kings when he made his empire after defeating the Parthians . The last " shahanshah " was ousted in 1979 following the Iranian Revolution . " Shahanshah " is usually translated as " king of kings " or simply " king " for ancient rulers of the Achaemenid , Arsacid , and Sassanid dynasties , and often shortened to " shah " for rulers since the Safavid dynasty in the 16th century . Indian subcontinent . The Sanskrit word for emperor is " Samrāṭ " or " Chakravarti " ( word stem : " samrāj " ) . This word has been used as an epithet of various Vedic deities , like Varuna , and has been attested in the Holy Rig Veda , possibly the oldest compiled book among the Indo - Europeans . " Chakravarti " refers to the king of kings . A " Chakravarti " is not only a sovereign ruler but also has feudatories . Typically , in the later Vedic age , a Hindu high king ( " Maharajah " ) was only called " Samrāṭ " after performing the Vedic " Rājasūya " sacrifice , enabling him by religious tradition to claim superiority over the other kings and princes . Another word for emperor is " sārvabhaumā " . The title of " Samrāṭ " has been used by many rulers of the Indian subcontinent as claimed by the Hindu mythologies . In proper history , most historians call Chandragupta Maurya the first " samrāṭ " ( emperor ) of the Indian subcontinent , because of the huge empire he ruled . The most famous Buddhist emperor was his grandson Ashoka the Great . Other dynasties that are considered imperial by historians are the Kushanas , Guptas , Vijayanagara , Hoysala and the Cholas . After India was invaded by the Mongol Khans and Turkic Muslims , the rulers of their major states on the subcontinent were titled " Sultān " , In this manner , the only empress - regnant ever to have actually sat on the throne of Delhi was Razia Sultan . For the period from 1877 to 1947 when British Emperors ruled colonial India as the pearl in the crown of the British Empire , see above . Africa . Ethiopia . In Ethiopia , the Solomonic dynasty used , beginning in 1270 , the title of " " which is literally " King of Kings " . The use of the " king of kings " style began a millennium earlier in this region , however , with the title being used by the Kings of Aksum , beginning with Sembrouthes in the 3rd century . Another title used by this dynasty was " Itegue Zetopia " . " Itegue " translates as Empress , and was also used by the only female reigning Empress , Zauditu , along with the official title " Negiste Negest " ( Queen of Kings ) . In 1936 , the Italian king Victor Emmanuel III claimed the title of Emperor of Ethiopia after Ethiopia was occupied by Italy during the Second Italo - Abyssinian War . After the defeat of the Italians by the Ethiopians who were assisted by soldiers from Britain in 1941 , Haile Selassie was restored to the throne but Victor Emmanuel did not relinquish his claim to the title until 1943 . The Rastafari claimed Selassie as God incarnate before and even more so after the Second World War ( see Rastafari movement ) because of his bravery in The Second Italo - Abyssinian War , the way he saved his country and his amazing speech to League of Nations . Subsequently , therefore , the word " Emperor " came to be used by its members as an honorific of exclusive usage for their divine king , as personified by the late Emperor of Ethiopia . Somalia . Ajuuraan Empire . The Ajuuraan Empire was a Somali Muslim empire that ruled over large parts of East Africa in the Middle Ages . It had a strong centralized administration and an aggressive military stance towards invaders , the Ajuuraan Empire successfully resisted an Oromo invasion from the west and a Portuguese incursion from the east during the Gaal Madow , meaning Black Christians , and the Ajuuraan - Portuguese wars . The House of Gareen was the ruling house and family of the Ajuuraan Empire . The Empire crumbled slowly in the 17th century . Warsangali Empire . The Warsangali Empire was a Somali imperial ruling house centered in northeastern and in some parts of southeastern Somalia . It was one of the largest Empire ever established in the territory , and , at the height of its power , included the Sanaag region and parts of the northeastern Bari region of the country , an area historically known as Maakhir or the " Maakhir Coast " . The Empire was founded in the late 13th century in northern Somalia by a group of Somalis from the Warsangali branch of the Darod clan , and was ruled by the descendants of the Gerad Dhidhin . The Empire was ruled by the house of Gerad Dhidhin . According to oral tradition , they fought against the Abyssinians and uprooted Christian communities in Galgala , a town that used to have churches and temples . The edifices are still present as historical landmarks . In honor of his accomplishments , Akil Dhahar ' s name is immortalized in the valley and mountains of the city known as Dhahar . In 1884 , the United Kingdom established the protectorate of British Somaliland through various treaties with the northern Somali States , including the Warsangali Empire . Central African Empire . In 1976 , President Jean - Bédel Bokassa of the Central African Republic , proclaimed the country to be an autocratic Central African Empire , and made himself Emperor as Bokassa I . The expenses of his coronation ceremony actually bankrupted the country . He was overthrown three years later and the republic was restored . East Asian tradition . China . The East Asian tradition is different from the Roman tradition , having arisen separately . What links them together is the use of the Chinese logographs 皇 ( " huáng " ) and 帝 ( " dì " ) which together or individually are imperial . Because of the cultural influence of China , China ' s neighbors adopted these titles or had their native titles conform in " hanzi " . In 221 BC , Ying Zheng , who was king of Qin at the time , proclaimed himself " shi huangdi " ( 始皇帝 ) , which translates as " first emperor " . " Huangdi " is composed of " huang " ( " august one " , 皇 ) and " di " ( " sage - king " , 帝 ) , and referred to legendary / mythological sage - emperors living several millennia earlier , of which three were " huang " and five were " di " . Thus Zheng became Qin Shi Huang , abolishing the system where the " huang " / " di " titles were reserved to dead and / or mythological rulers . Since then , the title " king " became a lower ranked title , and later divided into two gardes . Although not as popular , the title 王 " wang " ( king or prince ) was still used by many monarchs and dynasties in China up to the Taipings in the 19th century . 王 is pronounced " vương " in Vietnamese , " ō " in Japanese , and " wang " in Korean . The imperial title continued in China until the Qing Dynasty was overthrown in 1912 . The title was briefly revived from 12 December 1915 to 22 March 1916 by President Yuan Shikai and again in early July 1917 when General Zhang Xun attempted to restore last Qing emperor Puyi to the throne . Puyi retained the title and attributes of a foreign emperor , as a personal status , until 1924 . After the Japanese occupied Manchuria in 1931 , they proclaimed it to be the Empire of Manchukuo , and Puyi became emperor of Manchukuo . This empire ceased to exist when it was occupied by the Soviet Red Army in 1945 . In general , an emperor would have one empress ( " Huanghou " , 皇后 ) at one time , although posthumous entitlement to empress for a concubine was not uncommon . The earliest known usage of " huanghou " was in the Han Dynasty . The emperor would generally select the empress from his concubines . In subsequent dynasties , when the distinction between wife and concubine became more accentuated , the crown prince would have chosen an empress - designate before his reign . Imperial China produced only one reigning empress , Wu Zetian , and she used the same Chinese title as an emperor ( " Huangdi " , 皇帝 ) . Wu Zetian then reigned for about 15 years ( 690 - 705 AD ) . Japan . In ancient Japan , the earliest titles for the sovereign were either ヤマト大王 / 大君 ( " yamato ōkimi " , Grand King of Yamato ) , 倭王 / 倭国王 ( " waō " / " wakokuō " , King of Wa , used externally ) , or 治天下大王 ( " amenoshita shiroshimesu ōkimi " , Grand King who rules all under heaven , used internally ) . As early as the 7th century the word 天皇 ( which can be read either as " sumera no mikoto " , divine order , or as " tennō " , Heavenly Emperor , the latter being derived from a Tang Chinese term referring to the Pole star around which all other stars revolve ) began to be used . The earliest attested use of this term is on a wooden slat , or " mokkan " , that was unearthed in Asuka - mura , Nara Prefecture in 1998 and dated back to the reign of Emperor Temmu and Empress Jitō . The reading ' Tennō ' has become the standard title for the sovereign of Japan up to and including the present age . The term 帝 ( " mikado " , Emperor ) is also found in literary sources . Japanese monarchs placed themselves from 607 on equal footing with Chinese emperors in titulary terms , but rarely was the Chinese - style " Son of Heaven " term used . In the Japanese language , the word " tennō " is restricted to Japan ' s own monarch ; " kōtei " ( 皇帝 ) is used for foreign emperors . Historically , retired emperors have kept power over a child - emperor as de facto Regent . For a fairly long time , a shōgun ( formally the imperial generalissimo , but made hereditary ) or regent wielded actual political power . In fact , through much of Japanese history , the emperor has been little more than a figurehead . After World War II , all claims of divinity were dropped ( see Ningen - sengen ) . The Diet acquired all prerogative powers of the Crown , reverting the latter to a ceremonial role . By the end of the 20th century , Japan was the only country with an emperor on the throne . As of the early 21st century , Japan ' s succession law prohibits a female from ascending the throne . With the birth of a daughter as the first child of the current Crown Prince , Naruhito , Japan considered abandoning that rule . However , shortly after the announcement that Princess Kiko was pregnant with her third child , the proposal to alter the Imperial Household Law was suspended by Prime Minister Junichiro Koizumi . On 3 January 2007 , after the birth of her son , Prince Hisahito , Prime Minister Shinzo Abe announced that he would drop the proposal . Currently , many believe the new prince of Japan will ascend the throne , as the law defines . Historically , Japan has had eight reigning empresses who used the genderless title " Tennō " , rather than the female consort title " kōgō " ( 皇后 ) or " chūgū " ( 中宮 ) . There is ongoing discussion of the Japanese Imperial succession controversy . Although current Japanese law prohibits female succession , all Japanese emperors claim to trace their lineage to " Amaterasu " , the Sun Goddess of the Shintō religion . Korea . The rulers of Goguryeo ( 37 BC - 668 AD ) used the title of " Taewang " ( Hangul : 태왕 , Hanja : 太王 ) , literally translated as the " Greatest of the Kings " . Also some Silla ( 57 BC - 935 AD ) rulers including Beopheung and Jinheung used this title for their declaration of independence from the influence of Goguryeo . However , it does not signify " emperor " itself . The rulers of Balhae ( 698 - 926 ) internally called themselves " Seongwang " ( Hangul : 성왕 , Hanja : 聖王 ) . In 10th century , Gwangjong of Goryeo took the title of emperor himself as a means of enhancing the prestige of the monarchy , and it was first used in Korea . Many Goryeo sovereign alternately used both supreme king and emperor . After the Mongolian invasions ( 1231 – 1258 ) , however , Korea relinquished the imperial title . The rulers of the Joseon Dynasty ( 1392 - 1897 ) still used the term " King of the Joseon " ( Hangul : 조선국왕 , Hanja : 朝鮮國王 ) . In the First Sino - Japanese War of 1894 - ' 95 , Japan defeated the Qing Dynasty China , and the Treaty of Shimonoseki was concluded in which Japan had China recognize the independence and autonomy of Korea . However , King Gojong used term of " His Majesty the Great Monarch " ( Hangul : 대군주폐하 , Hanja : 大君主陛下 ) not officlal imperial title . In 1897 , King Gojong proclaimed the founding of the Korean Empire ( 1897 – 1910 ) , and became emperor of Korea . Emperor Gojong declared the new era name " Gwangmu " ( Hangul : 광무 , Hanja : 光武 , Warrior of light ) . Korean Empire maintained their state until 1910 - though it was an Empire by name , in fact in the process of being absorbed by Japan . Mongol . The title Khagan ( khan of khans or grand khan ) was held by Genghis Khan , founder of the Mongol Empire in 1206 . After 1271 , the emperors of the Yuan Dynasty also took the Chinese title " huangdi " , or Chinese emperor . Only the Khagans from Genghis Khan to the fall of the Yuan Dynasty in 1368 are normally referred to as Emperors in English . Vietnam . Ngô Quyền , the first ruler of Đại Việt as an independent state , used the title " Vương " ( 王 , " King " ) . However , after the death of Ngô Quyền , the country immersed in a civil war known as War of the 12 Lords that lasted for over 20 years . In the end , Đinh Bộ Lĩnh unified the country after defeating all the warlords and became the first ruler of Đại Việt to use the title " Hoàng Đế " ( 皇帝 , " Emperor " ) in 968 . Succeeding rulers in Vietnam then continued to use this Emperor title until 1806 when this title was stopped being used for a century . Đinh Bộ Lĩnh wasn ' t the first to claim the title of " Đế " ( 帝 , " Emperor " ) . Before him , Lý Bí and Mai Thúc Loan also claimed this title . However , their rules were very short lived . The Vietnamese emperors also gave this title to their ancestors who were lords or influence figures in the previous dynasty like the Chinese emperors . This practice is one of many indications of the idea " Vietnam ' s equality with China " which is remained intact up to twentieth century . In 1802 the newly established Nguyễn dynasty requested canonization from Chinese Jiaqing Emperor and got the title " Quốc Vương " ( 國王 , " King of a State ) " and the name of the country as " An Nam " ( 安南 ) instead " Đại Việt " ( 大越 ) . To avoid unnecessary armed conflicts , the Vietnamese rulers accepted this in diplomatic relation and use the title Emperor only domestically . However , Vietnamese rulers never accepted the vassalage relationship with China and always refused to come to Chinese courts to pay homage to Chinese rulers ( a sign of vassalage acceptance ) . China waged a number of wars against Vietnam throughout history , and after each failure , settled for the tributary relationship . The Yuan dynasty under Kublai Khan waged three wars against Vietnam to force it into a vassalage relationship but after successive failures , Kublai Khan ' s successor , Temür Khan , finally settled for a tributary relationship with Vietnam . Vietnam sent tributary missions to China once in three years ( with some periods of disruptions ) until the 19th century , Sino - French War France replaced China in control of northern Vietnam . The emperors of the last dynasty of Vietnam continued to hold this title until the French conquered Vietnam . The emperor , however , was then a puppet figure only and could easily be disposed of by the French for more pro - France figure . Japan took Vietnam from France and the Axis - occupied Vietnam was declared an empire by the Japanese in March 1945 . The line of emperors came to an end with Bảo Đại , who was deposed after the war , although he later served as head of state of South Vietnam from 1949 to 1955 . Oceania . The lone holders of the imperial title in Oceania were the heads of the semi - mythical Tu ' i Tonga Empire . Fictional uses . There have been many fictional emperors in movies and books . To see a list of these emperors , see .