Brunswick-Lüneburg was a medieval state within the Holy Roman Empire. As the name implies, the main cities of this state were Brunswick and Lüneburg.
The state emerged from the inheritance of the first Saxon state of Henry the Lion. Shortly after Henry's death the duchy of Saxony began to decline. Several mini-states came into being, among them Brunswick and Lüneburg.
The first duke of Brunswick-Lüneburg was Otto the child, who reigned from 1235 on. After 1267 the duchy was split into two partial states (which later became a multitude of partial states), but all of them were ruled by the Welfen[?] dynasty and still formed a common state. The centres of power moved in the meantime from Brunswick and Lüneburg to Celle and Wolfenbüttel.
One of the collateral lines was the line of the dukes of Calenberg, who managed to gain all the territory of the former duchy except for Brunswick. The city of Hanover was the residence of the Calenberg line. Therefore Calenberg (sometimes also called Calenberg-Celle) was made an electorate by the Holy Roman Emperor 1692. It was then known under many different names (Brunswick-Lüneburg, Calenberg, Hanover), but eventually became the state of Hanover.
Brunswick retained its independency from Hanover and was a duchy within the German Empire until 1918.
