noble_family charlotte of mecklenburg-strelitz
The Holy Roman Empire was a multi - ethnic complex of territories in central Europe that developed during the Early Middle Ages and continued until its dissolution in 1806 . The largest territory of the empire after 962 was the Kingdom of Germany , though it also came to include the Kingdom of Bohemia , the Kingdom of Burgundy , the Kingdom of Italy , and numerous other territories . The Kingdom of Germany or German Kingdom (" Teutonic Kingdom ") developed out of the eastern half of the former Carolingian Empire . Like Anglo - Saxon England and medieval France , it began as " a conglomerate , an assemblage of a number of once separate and independent ... " gentes " [ peoples ] and " regna " [ kingdoms ]." East Francia (" Ostfrankenreich ") was formed by the Treaty of Verdun in 843 , and was ruled by the ___MASK85___ until 911 , after which the kingship was elective . The initial electors were the rulers of the stem duchies , who generally chose one of their own . After 962 , when Otto I was crowned emperor , the kingdom formed the bulk of the Holy Roman Empire , which also included Italy ( after 951 ), Bohemia ( after 1004 ) and Burgundy ( after 1032 ). The King of Hanover ( German : König von Hannover ) was the official title of the head of state and hereditary ruler of the Kingdom of Hanover , beginning with the proclamation of the King of the United Kingdom George III , as " King of Hanover " during the Congress of Vienna , on 12 October 1814 at Vienna , and ending with the kingdom ' s annexation by Prussia on 20 September 1866 . Charlotte of Mecklenburg - Strelitz ( Sophia Charlotte ; 19 May 1744 -- 17 November 1818 ) was the wife of King George III . She was Queen of Great Britain and Ireland from her marriage in 1761 until the union of the two kingdoms in 1801 , after which she was Queen of the United Kingdom of Great Britain and Ireland until her death in 1818 . She was also the Electress of Hanover in the Holy Roman Empire until the promotion of her husband to King of Hanover on 12 October 1814 , after which she was also queen consort of Hanover . Queen Charlotte was a patroness of the arts and an amateur botanist , who helped expand Kew Gardens . George III and Charlotte had 15 children , 13 of whom survived to adulthood . She was distressed by her husband ' s bouts of physical illness and insanity , which became permanent in later life and resulted in their eldest son being appointed Prince Regent in 1811 . The Kingdom of Hanover was established in October 1814 by the Congress of Vienna , with the restoration of George III to his Hanoverian territories after the Napoleonic era . It succeeded the former Electorate of Brunswick - Lüneburg ( known informally as the Electorate of Hanover ), and joined with 38 other sovereign states in the German Confederation in June 1815 . The kingdom was ruled by the ___MASK41___ , a younger branch of the House of Welf , in personal union with Great Britain and Ireland until 1837 , before being conquered by Prussia in 1866 and transformed into a Prussian province . Along with the rest of Prussia , Hanover became part of the German Empire upon unification in January 1871 . Briefly revived as the State of Hanover in 1946 , the state was subsequently merged with some smaller states to form the current state of Lower Saxony in West Germany , later Germany .