Duke of Brunswick and Lüneburg

Duchy of Brunswick-Lüneburg
Herzogtum Braunschweig-Lüneburg
Duchy
1235–1806
Coat of arms
Brunswick-Lüneburg as part of the Holy Roman Empire, c. 1648
Capital		Brunswick, Lüneburg
Languages		West Low German
Government		Duchy
Historical era		Middle Ages
•	Henry the Lion defeated; Saxony divided; Henry reinvested with Welf allod	1180 1181
•	Allod elevated to Duchy of Brunswick and Lüneburg	1235
•	Partition into Lüneburg and Brunswick	1269
•	Grubenhagen formed	1291
•	Göttingen formed	1345
•	Brunswick splits into Wolfenbüttel and Calenberg	1432
•	Joined Electoral Rhenish Circle
•	The end of the Holy Roman Empire	1806
Preceded by Succeeded by Duchy of Saxony Electorate of Hanover Duchy of Brunswick
Today part of		Germany

The Duchy of Brunswick-Lüneburg (German: Herzogtum Braunschweig-Lüneburg), or more properly the Duchy of Brunswick and Lüneburg, was an historical ducal state from the late Middle Ages until the late Early Modern era within the North-Western domains of the Holy Roman Empire of the German Nation, in what is now northern Germany. Its name came from the two largest cities in the territory: Brunswick and Lüneburg.

The dukedom emerged in 1235 from the allodial lands of the House of Welf in Saxony and was granted as an imperial fief to Otto the Child, a grandson of Henry the Lion. The duchy was divided several times during the High Middle Ages amongst various lines of the House of Welf, but the rulers all continued to be styled as the "Duke of Brunswick-Lüneburg" in addition to their various particular titles. By 1692, the territories had consolidated to two: the Electorate of Brunswick-Lüneburg (Hanover) and the Principality of Brunswick-Wolfenbüttel.

In 1714, the Hanoverian branch of the family succeeded to the throne of Great Britain, which they would rule in personal union with Hanover until 1837. For this reason, many cities and provinces in former British colonies are named after Brunswick or Lüneburg. Ironically, the Hanoverians never ruled Brunswick while they held the British throne, as the city was part of neighboring Brunswick-Wolfenbüttel. After the Congress of Vienna in 1814/15, the Brunswick-Lüneburg territories became the Kingdom of Hanover and the Duchy of Brunswick.