Photograph of H. M. Constantine I, King of Greece. Brother-in-law to Kaiser Wilhelm II of Germany, he insisted on Greek neutrality during World War I, but was forced to retire in favour of his son Alexander by the rival government of Eleutherios Venizelos and the Allies (1917). In 1920, he ws restored to the throne by plebiscite, but after a military revolt in 1922, abdicated again in favour of his son, George II.