Celle is a town on the River Aller, a tributary of the Weser, northeast of Hanover. It became the residence of the Dukes of Brunswick-Lüneburg in the late 14th century. As a result of a long dispute with the Electors of Saxony over the possession of Lüneburg and its Duchy, the town of Lüneburg had acquired too much independence to be a satisfactory residence for the Duke.
The name of Brunswick-Celle for the Duchy of Brunswick-Lüneburg was especially used after a partition of 1527, when Ernest, the middle son of the abdicated Duke Henry, received the major part because his elder brother had made an unequal marriage. After the death of Ernest’s eldest son in 1559, the third son, William, prevailed in a family dispute, though in 1569 he gave three small districts, including Dannenberg, to his elder brother Henry.
The problems that arose from partitioning the family territories led the seven sons of Duke William to cast lots to decide which one of them should marry and so beget the only legitimate heirs. Four of the brothers, all unmarried, succeeded in turn, the first in 1592 and the last in 1636. In 1635 the family acquired Calenberg from the extinct Wolfenbüttel line, which acted as a second Duchy, held by the heir. Its first Duke was George, 1636-41, the fortunate brother who had won the marriage lottery, though he rather limited its effectiveness by himself begetting four sons, who all succeeded in turn to Calenberg, the two eldest also succeeding to Celle.
George’s second son, Duke George William, Duke at Celle, 1665-1705, had been prepared to leave marriage to his youngest brother, Ernest Augustus, the future Elector of Hanover, but fell in love with a Huguenot lady, had a daughter, and later married his lady morganatically. This complicated the succession, though the daughter was illegitimate, or, if legitimated, still only the child of a morganatic marriage. The two brothers solved the problem of possible claims by a future husband by marrying George’s daughter to Ernest Augustus’s son. Though the marriage later broke down, it had by then produced an heir.
The rather more simple expedient of introducing primogeniture to keep the inheritance intact was adopted when Ernest Augustus was made an Elector in 1692. His son, George Louis, succeeded his father as Elector of Hanover in 1698 and on the death of his uncle George William in 1705 became Duke of Brunswick-Celle, thus reuniting the Brunswick-Lüneburg lands. In 1714 by way of his mother and an Act of Parliament he became King George I of Great Britain.