Question: John Hamilton-Leslie fought on the side of a King of Great Britain and Ireland who was the ruler of the Duchy and Electorate of Brunswick-Luneburg in what empire?

Context paragraphs:
John Hamilton-Leslie, 9th Earl of Rothes: John Hamilton-Leslie, 9th Earl of Rothes (1679–1722) was a Scottish nobleman who fought on the side of George I during the Jacobite rising of 1715.

Governance of England: There has not been a government of England since 1707 when the Kingdom of England ceased to exist as a sovereign state, as it merged with the Kingdom of Scotland to form the Kingdom of Great Britain.  Kingdom of Great Britain continued from 1707 until 1801 when it merged with the Kingdom of Ireland to form the United Kingdom of Great Britain and Ireland, which itself became the United Kingdom of Great Britain and Northern Ireland (UK) in 1922 (in reality; in name in 1927) upon independence for most of the island of Ireland.  The UK since then has gone through significant change to its system of government, with devolved parliaments, assemblies and governments in Scotland, Wales and Northern Ireland.  England, however, remains under the full jurisdiction, on all matters, of the Parliament of the United Kingdom of Great Britain and Northern Ireland and the UK government as no devolved administration has been created for England within the new structure.  This situation has led to the anomaly, known as the West Lothian question, which is that Scottish Members of Parliament (MPs) are able to vote on legislation that affects only England whereas English MPs can not vote on certain Scottish matters due to devolution.  In some cases, such as top-up university tuition fees and foundation hospitals, the votes of Scottish MPs have been crucial in helping pass legislation for England that the majority of English MPs have opposed.

Heil dir, Hannover: Heil dir, Hannover (English: Hail to thee, Hanover), was the national anthem of the Electorate, and later Kingdom of Hanover, adopted in the early 18th century.  Like other many rulers in the 17th & 18th century, George I of Hanover and Great Britain instructed George Handel to create an anthem.  Handel's melody remained the United Kingdom of Great Britain and Ireland's anthem after the end of the personal union in 1837.  Also many other German states made this melody their anthem.  For example, it was used in the Grand Duchy of Oldenburg and the Kingdoms of Bavaria and Prussia.  After 1871, it became the anthem of the German Empire with the lyrics "Heil dir im Siegerkranz".  The last Holy Roman Emperor and German king, Francis II, was very impressed by Handel's theme an instructed his Court musician Haydn to create the "Kaiserhymne", which became his imperial anthem and continued to be used in the new Austrian Empire after he dissolved the Holy Roman Empire.

George I of Great Britain: George I (George Louis; German: "Georg Ludwig" ; 28 May 1660 – 11 June 1727) was King of Great Britain and Ireland from 1 August 1714 until his death, and ruler of the Duchy and Electorate of Brunswick-Lüneburg (Hanover) in the Holy Roman Empire from 1698.

Monarchy of Ireland: A monarchical system of government existed in Ireland from ancient times until, for what became the Republic of Ireland, the mid-twentieth century.  Northern Ireland, as part of the United Kingdom, remains under a monarchical system of government.  The Gaelic kingdoms of Ireland ended with the Norman invasion of Ireland, when the kingdom became a fief of the Holy See under the Lordship of the King of England.  This lasted until the Parliament of Ireland conferred the crown of Ireland upon King Henry VIII of England during the English Reformation.  The monarch of England held the crowns of England and Ireland in a personal union.  The Union of the Crowns in 1603 expanded the personal union to include Scotland.  The personal union between England and Scotland became a political union with the enactments of the Acts of Union 1707, which created the Kingdom of Great Britain.  The crowns of Great Britain and Ireland remained in personal union until it was ended by the Acts of Union 1800, which united Ireland and Great Britain into the United Kingdom of Great Britain and Ireland from January 1801 until December 1922.

Treaties of Reichenbach (1813): The Treaties of Reichenbach were a series of agreements signed in Reichenbach (present-day Dzierżoniów) between Great Britain, Prussia, Russia, and Austria.  These accords served to establish and strengthen a united coalition force against Napoleon I of France.  On 14 June 1813 the Treaty of Reichenbach was signed between Great Britain and Prussia.  Based on the terms of the accord, Britain agreed to provide Prussia a subsidy of 666,666 pounds sterling in order for Prussia to maintain its force of 80,000 troops.  In exchange for this aid, the king of Prussia agreed to cede the principality of Hildesheim and other territories to the Electorate of Hanover.  On 15 June 1813 the Treaty of Reichenbach was signed between Great Britain and Russia.  Based on the terms of the accord, Great Britain agreed to provide Russia with a subsidy of 1,333,334 pounds sterling in order for Russia to maintain its force of 160,000 troops.  On 27 June 1813 the Treaty of Reichenbach (also known as the "Reichenbach Convention") was signed between Prussia, Russia, and Austria.  Based on the terms of the accord, Austria agreed to declare war against Napoleon if he rejected its conditions of peace.

List of monarchs of Prussia: The monarchs of Prussia were members of the House of Hohenzollern who were the hereditary rulers of the former German state of Prussia from its founding in 1525 as the Duchy of Prussia.  The Duchy had evolved out of the Teutonic Order, a Roman Catholic crusader state and theocracy located along the eastern coast of the Baltic Sea.  The Teutonic Knights were under the leadership of a Grand Master, the last of whom, Albert, converted to Protestantism and secularized the lands, which then became the Duchy of Prussia.  The Duchy was initially a vassal of the Kingdom of Poland, as a result of the terms of the Prussian Homage whereby Albert was granted the Duchy as part of the terms of peace following the Prussian War.  When the main line of Prussian Hohenzollerns died out in 1618, the Duchy passed to a different branch of the family, who also reigned as Electors of Brandenburg in the Holy Roman Empire.  While still nominally two different territories, Prussia under the suzerainty of Poland and Brandenburg under the suzerainty of the Holy Roman Empire, the two states are known together historiographically as Brandenburg-Prussia.  Following the Second Northern War, a series of treaties freed the Duchy of Prussia from any vassalage to any other state, making it a fully sovereign Duchy in its own right.  This complex situation (where the Hohenzollern ruler of the independent Duchy of Prussia was also a subject of the Holy Roman Emperor as Elector of Brandenburg) laid the eventual groundwork for the establishment of the Kingdom of Prussia in 1701.  For diplomatic reasons, the rulers of the state were known as the King in Prussia from 1701 to 1772; largely because they still owed fealty to the Emperor as Electors of Brandenburg, the "King in Prussia" title (as opposed to "King of Prussia") avoided offending the Emperor.  As the Prussian state grew through several wars and diplomatic moves throughout the 18th century, it became apparent that Prussia had become a Great Power that did not need to submit meekly to the Holy Roman Empire.  By 1772, the pretense was dropped, and the style "King of Prussia" was adopted.  Thus it remained until 1871, when in the aftermath of the Franco-Prussian War, the King of Prussia Wilhelm I was crowned German Emperor.  From that point forward, though the Kingdom of Prussia retained its status as a constituent state of the German Empire, all remaining Kings of Prussia also served as German Emperor, and that title took precedence.

Great Britain at the 2016 Summer Olympics: The United Kingdom of Great Britain and Northern Ireland competed as Great Britain at the 2016 Summer Olympics in Rio de Janeiro, Brazil, from 5 to 21 August 2016.  The United Kingdom was represented by the British Olympic Association (BOA), and the team of selected athletes was also known as Team GB.  British athletes have appeared in every Summer Olympic Games of the modern era, alongside Australia, France, Greece, and Switzerland, though Great Britain is the only country to have won at least one gold medal at all of them.  Although the British Olympic Association is the National Olympic Committee (NOC) for Great Britain and Northern Ireland, Northern Irish athletes can choose whether to compete for Great Britain or for the Republic of Ireland, as they are entitled to citizenship of either nation under the Good Friday Agreement.  In 2016 Northern Ireland born representatives in Team GB included returning rowers Alan Campbell, Peter Chambers and Richard Chambers, archer Patrick Huston and four members of the men's field hockey team: David Ames, Mark Gleghorne, Iain Lewers and Ian Sloan.  The team also represents, and included representation from, the Crown dependencies, among which were Guernsey's Heather Watson and Carl Hester, and from the ten of the thirteen British Overseas Territories represented by the BOA rather than their own NOC, whose representatives include Turks and Caicos-born sprinter Delano Williams and Anguillan-born long jumper Shara Proctor

Irish migration to Great Britain: Irish migration to Great Britain has occurred from the earliest recorded history to the present.  There has been a continuous movement of people between the islands of Ireland and Great Britain due to their proximity.  This tide has ebbed and flowed in response to politics, economics and social conditions of both places.  Ireland was a feudal Lordship of the Kings of England between 1171 and 1541; a Kingdom in personal union with the Kingdom of England and Kingdom of Great Britain between 1542 and 1801; and politically united with Great Britain as the United Kingdom of Great Britain and Ireland between 1801 and 1922.  Today, Ireland is divided between the independent Republic of Ireland and Northern Ireland.

Duchy of Württemberg: The Duchy of Württemberg (German: "Herzogtum Württemberg" ) was a duchy located in the south-western part of the Holy Roman Empire.  It was a member of the Holy Roman Empire from 1495 to 1806.  The dukedom's long survival for nearly four centuries was mainly due to its size, being larger than its immediate neighbors.  During the Protestant Reformation, Württemberg faced great pressure from the Holy Roman Empire to remain a member.  Württemberg resisted repeated French invasions in the 17th and 18th centuries.  Württemberg was directly in the path of French and Austrian armies who were engaged in the long rivalry between the House of Bourbon and the House of Habsburg.  In 1803, Napoleon raised the duchy to be the Electorate of Württemberg of the Holy Roman Empire, and when he abolished the Empire in 1806, the Electorate was elevated as the Kingdom of Württemberg.

Supporting paragraphs: John Hamilton-Leslie, 9th Earl of Rothes George I of Great Britain
Answer: Holy Roman Empire