Kaiser Wilhelm II was the leader of Germany during WWI. He became emperor in 1888 after the death of Frederick II and was forced to abdicate in 1918.
Wilhelm supported Austria-Hungary in its retaliatory efforts against Serbia after the assassination of Archduke Ferdinand in 1914 and led the German forces in the ensuing war. He did not expect to trigger a response from Russia, France and Great Britain and was eventually edged out of military decisions as the war raged on. With the entrance of the United States into the war, Germany's chances of victory were nullified, and Wilhelm was forced to abdicate on November 9, 1918. He lived the rest of his life in exile in Holland and was never tried for war crimes.