The Principality of Lippe existed until the end of the German monarchies in 1918. In 1905, with the death of Alexander, Prince of Lippe, the senior Lippe-Detmold branch of the family became extinct and Count Leopold of Lippe-Biesterfeld (head of the non-ruling junior branch line Lippe-Biesterfeld) succeeded him as Prince, after an Imperial court ruling, in fact against the wishes of Wilhelm II, German Emperor, who would have preferred his brother-in-law Prince Adolf of Schaumburg-Lippe to succeed. Leopold IV continued to rule until the German Revolution of 1918. During the revolution, the ruling Princes of Lippe and Schaumburg-Lippe were forced to abdicate, ending the family's 795-year rule. In 1928, Prince Leopold's three sons by his first wife signed up to the Nazi Party. The eldest, Prince Ernst, was reputedly the first German prince to do so.