claim to Hanover. By a law of 1879, the Duchy of Brunswick established a temporary council of regency to take over at the Duke's death. If Ernest Augustus–who had been created the Duke of Cumberland in the British peerage–were unable to succeed, the council would also be empowered to appoint a regent. With William's death in 1884, the Wolfenbüttel line came to an end. The Duke of Cumberland then proclaimed himself Ernest Augustus, Duke of Brunswick. However, since he still claimed to be the rightful King of Hanover, the Federal Council ruled that he would violate the peace of the German Empire if he succeeded to Brunswick. Lengthy negotiations ensued, but were never resolved. Regency (1884–1913) Two regents were appointed: first, Prince Albert of Prussia until his death in 1906, and then Duke John Albert of Mecklenburg. Ernest Augustus (1913–1918) The need for a Regent ended in 1913. The Duke of Cumberland's eldest son having died in 1912, the elderly Duke renounced Brunswick in favor of his youngest son, Ernest Augustus, who married Emperor Wilhelm II's daughter, swore allegiance to the German Empire and renounced all claims to Hanover. Accordingly, he was allowed to ascend the throne of the Duchy in November 1913. In the midst of the German revolutions of 1918, the Duke had to abdicate, and the Free State of Brunswick was founded as a member state of the Weimar Republic. Dukes and Regents of Brunswick House of Brunswick-Dannenberg 1815–1830: Charles II, son of Frederick William. Forced to flee Brunswick in 1830 and succeeded by his brother. 1830–1884: William VIII. Brother of Charles II. Last of the Brunswick line, following which the legal succession passed to the Hanoverian royal family, which had been dispossessed by Prussia following the Austro-Prussian War of 1866. Regency 1885–1906: Albert, Prince of Prussia, regent. The German government prevented the succession of the Hanoverian Duke of Cumberland to the throne of Brunswick and substituted a Prussian regent for the Duke. 1907–1913: Duke John Albert of Mecklenburg, regent House of Hanover 1913–1918: Ernest Augustus Titular Dukes Ernest Augustus, Crown Prince of Hanover (1884–1913), renounced the aforementioned Ernest Augustus, the deposed duke of Brunswick (1918–1953), son of the previous Prince Ernst August of Hanover (1914–1987) (1953–1987) Prince Ernst August of Hanover (born 1954) (1987–present) For further information on the governments of Brunswick from 1918 on, see Free State of Brunswick. Geography The Duchy of Brunswick consisted