Major division of the Duchy of Brunswick. Lüneburg is southeast of Hamburg, on the River Ilmenau, a tributary of the Elbe. Its lands formed the original territory of the Welf dynasty in northern Germany, inherited through Wulfhilda, the wife of Duke Henry the Black of Bavaria and one of the heiresses of the last Billung Duke of Saxony, who died in 1106. When their grandson, Henry the Lion, died in 1195 his youngest son William took Lüneburg as his share of the family lands. When he died in 1213, his son was still young, whence the nickname Otto der Kind, Otto the Child.
In 1235, with all the Welf inheritance in northern Germany regathered together, Otto was made Duke of Brunswick and Lüneburg. In 1267 his sons, Albert I and John I, partitioned the Duchy, Lüneburg being held by John and his descendants until they died out in the male line in 1369. A long struggle then followed. One daughter of the last Duke had married a brother of the Elector of Saxony, and had a son, whilst the other daughter had married a kinsman of the Göttingen branch of the family, who was designated heir to his father-in-law. Both the sons-in-law died before the Duke.
When he died in 1369, was his heir the Saxon grandson or was it a prince representing his dead Brunswick son-in-law and heir? The matter took almost twenty years to resolve, a conclusion which was hastened by the death of the Saxon grandson without issue in 1385. Duke Bernard I of the Göttingen line became Duke in Lüneburg in 1388, exchanged it for Wolfenbüttel with his younger brother in 1409, and in the final family settlement in 1428 received it back from his nephews, who received Wolfenbüttel from him and kept Calenberg from the Lüneburg inheritance.
As a result of the struggle and the large degree of independence enjoyed by the town of Lüneburg, Celle became the residence of the Dukes. This new Lüneburg line (later called the Middle House of Lüneburg) was held by the Celle Duke. In 1559 the younger of two surviving brothers outmanoevred his elder brother, though ten years later he threw him a few scraps of territory (Brunswick-Dannenberg). The Lüneburg lands were enlarged in 1634-6 after the extinction of the Brunswick-Wolfenbüttel line with the lands of Calenberg and Göttingen, which became a Duchy for the second senior prince of the Lüneburg line.
After 1679 the Lüneburg lands were held by the two brothers, George William of Celle and Ernest Augustus of Calenberg. Their joint object was to secure an Electorate for the family and for Ernest Augustus (the self-effacing George William was only morganatically married).
The military circumstances of the Emperor Leopold I persuaded him to grant the electorate in 1692 to an undeniably Protestant prince. Officially Ernest Augustus became the Elector of Brunswick-Lüneburg, but his territory was almost always called Hanover. The lands of Brunswick-Lüneburg were united in 1705 when George Louis, Elector of Hanover, succeeded his uncle and father-in-law in Celle.