In 1870, after the Battle of Sedan, French Emperor Napoleon III was sent as a prisoner to Schloss Wilhelmshöhe before going into exile in Britain. From 1899, German Emperor Wilhelm II, who went to school in Kassel, chose Wilhelmshöhe as his summer residence, which turned the castle and the park into a centre of European politics for the next two decades. After the armistice which ended World War I, the Oberste Heeresleitung led by Paul von Hindenburg organized and led the withdrawal and demobilization of the German troops from here from November 1918 to February 1919.
