Principality of Calenberg-Göttingen. After his death in 1636 his younger brother George became its ruler. He was successful as a general on the Swedish side and he also succeeded in 1637 in recovering the country and especially the towns for the Welfs. He initially ruled out of occupied Hildesheim, but then moved his residence to Hanover, which he also had built as a fortress. After his death in 1641 a separate peace was hastily concluded with the emperor, which had to be paid for by the return of the land acquired during the Hildesheim Diocesan Feud. George's sons, Christian Louis, George William, John Frederick and Ernest Augustus then ruled the Principality of Calenberg-Göttingen in succession. Elevation to an electorate In 1665 the Principality of Grubenhagen, whose line had died out in 1596 and over which the lines of Lüneburg and Wolfenbüttel had long fought in the Imperial Chamber Court, was also finally added to the Calenberg dynasty. George's youngest son, Ernest Augustus, who ruled from 1679, carried on the successful policies of his father and his brothers. In 1689 the Calenbergs also inherited Saxe-Lauenburg. Ernest Augustus switched to the side of the Emperor and introduced primogeniture, contrary to the direction of his father. In 1692 for his services to the Emperor, Ernest Augustus was rewarded after a long struggle with the title of the ninth electorate. Officially he was now the Elector of Brunswick-Lüneburg and his government was called the "Electoral Brunswick-Lüneburg Government". In 1705 it was enhanced further by the inheritance of the Principality of Lüneburg, whereby all the estates of the Welfs, apart from the Principality of Brunswick-Wolfenbüttel, became united under the line also known as the House of Hanover from which the British royal throne are descended. Economic and social history The Principality of Calenberg was initially a rather insignificant territory and Welf lordship developed here quite late. By the reign of George of Calenberg in 1636, the principality had experienced 140 years of almost continuously poor government that cared little about the state. In the Middle Ages and the Renaissance the cultural centres lay outside Calenberg in the towns of Brunswick, Hildesheim and Lüneburg. New centres were created at the residences of Wolfenbüttel and Celle. Even the city of Hanover was not governed by the Calenberg princes until 1636. The other towns remained unimportant. Only after the reign of George of Calenberg and its subsequent elevation