Duchy of Brunswick-Lüneburg in the context of "Elector of Hanover"

George I (George Louis; German: Georg Ludwig; 28 May 1660 – 11 June 1727) was King of Great Britain and Ireland from 1 August 1714 and ruler of the Electorate of Hanover within the Holy Roman Empire from 23 January 1698 until his death in 1727. He was the first British monarch of the House of Hanover.

Born in Hanover to Ernest Augustus and Sophia of Hanover, George inherited the titles and lands of the Duchy of Brunswick-Lüneburg from his father and uncles. In 1682, he married his cousin Sophia Dorothea of Celle, with whom he had two children; he also had three daughters with his mistress Melusine von der Schulenburg. George and Sophia Dorothea divorced in 1694. A succession of European wars expanded George's German domains during his lifetime; he was ratified as prince-elector of Hanover in 1708.

The Electorate of Hanover (German: Kurfürstentum Hannover or simply Kurhannover) was an electorate of the Holy Roman Empire located in northwestern Germany that arose from the Principality of Calenberg. Although formally known as the Electorate of Brunswick-Lüneburg (German: Kurfürstentum Braunschweig-Lüneburg), it made Hanover its capital city. For most of its existence, the electorate was ruled in personal union with Great Britain and Ireland following the Hanoverian Succession.

The Duchy of Brunswick-Lüneburg had been split in 1269 between different branches of the House of Welf. The Principality of Calenberg, ruled by a cadet branch of the family, emerged as the largest and most powerful of the Brunswick-Lüneburg states. In 1692, the Holy Roman Emperor elevated the Prince of Calenberg to the College of Electors, creating the new Electorate of Brunswick-Lüneburg. The fortunes of the electorate were tied to those of Great Britain by the Act of Settlement 1701 and Act of Union 1707, which settled the succession to the British throne on Queen Anne's nearest Protestant relative, the Electress Sophia of Hanover, and her descendants.

The Principality of Brunswick-Wolfenbüttel (German: Fürstentum Braunschweig-Wolfenbüttel) was a subdivision of the Duchy of Brunswick-Lüneburg, whose history was characterised by numerous divisions and reunifications. It had an area of 3,828 square kilometres in the mid 17th century. Various dynastic lines of the House of Welf ruled Brunswick-Wolfenbüttel until the dissolution of the Holy Roman Empire in 1806. As a result of the Congress of Vienna, its successor state, the Duchy of Brunswick, was created in 1815.

Hanover (/ˈhænoʊvər, -nəv-/ HAN-oh-vər, HAN-ə-vər; German: Hannover [haˈnoːfɐ] ; Low German: Hannober) is the capital and largest city of the German state of Lower Saxony. Its population of 535,932 (2021) makes it the 13th-largest city in Germany as well as the fourth-largest in northern Germany after Berlin, Hamburg and Bremen. Hanover's urban area comprises the towns of Garbsen, Langenhagen and Laatzen and has a population of about 791,000 (2018). The Hanover Region has approximately 1.16 million inhabitants (2019) and is the largest in the Hanover–Braunschweig–Göttingen–Wolfsburg Metropolitan Region, the 17th biggest metropolitan area by GDP in the European Union.

Before it became the capital of Lower Saxony in 1946, Hanover was the capital of the Principality of Calenberg (1636–1692), the Electorate of Hanover (1692–1814), the Kingdom of Hanover (1814–1866), the Province of Hanover of the Kingdom of Prussia (1868–1918), the Province of Hanover of the Free State of Prussia (1918–1947) and of the State of Hanover (1946). From 1714 to 1837 Hanover was by personal union the family seat of the Hanoverian Kings of the United Kingdom of Great Britain and Ireland, under their title of the dukes of Brunswick-Lüneburg (later described as the Elector of Hanover).

The Principality of Calenberg was a dynastic division of the Welf Duchy of Brunswick-Lüneburg established in 1432. Calenberg was ruled by the House of Hanover (from the Principality of Lüneburg) from 1635 onwards; the princes received the ninth electoral dignity of the Holy Roman Empire in 1692. Their territory became the nucleus of the Electorate of Hanover, ruled in personal union with the Kingdom of Great Britain from 1714 onwards. The principality received its name from Calenberg Castle, a residence of the Brunswick dukes.

Albert the Tall (Latin: Albertus Longus, German: Albrecht der Große; 1236 – 15 August 1279), a member of the House of Welf, was Duke of Brunswick-Lüneburg from 1252 and the first ruler of the newly created Principality of Brunswick-Wolfenbüttel from 1269 until his death.

John (c. 1242 – 13 December 1277), a member of the House of Welf, was Duke of Brunswick-Lüneburg from 1252 until his death. He initially reigned jointly with his brother, Albert the Tall, until the partition of the duchy in 1269, when John became the first ruler of the newly created Principality of Lüneburg.