Braunschweig-Lüneburg

Duchy of Brunswick-Lüneburg
Herzogtum Braunschweig-Lüneburg
State of the Holy Roman Empire
1235–1806
Coat of arms
Brunswick-Lüneberg as part of the Holy Roman Empire, c. 1648
Capital		Brunswick, Lüneburg
Languages		West Low German
Government		Principality
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

The Duchy of Brunswick-Lüneburg (German: Herzogtum Braunschweig-Lüneburg), or more properly 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.

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. Its name came from the two largest towns in the territory: Brunswick and Lüneburg. 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. The individual principalities making up the duchy continued to exist until the end of the Holy Roman Empire in 1806. Following the Congress of Vienna in 1814/15, the territories became part of the Kingdom of Hanover and Duchy of Brunswick.

When the imperial ban was placed on Henry the Lion in 1180, he lost his titles as Duke of Saxony and Duke of Bavaria. He went into exile for several years, but was then allowed to stay on the (allodial) estates inherited from his mother's side until the end of his life.