Constantine’s disagreement with Eleftherios Venizelos over whether Greece should enter World War I led to the National Schism. He forced Venizelos to resign twice, but in 1917 he left Greece, after threats by the Entente forces to bombard Athens; his second son, Alexander, became king. After Alexander's death, Venizelos' defeat in the 1920 legislative elections, and a plebiscite in favor of his return, Constantine was reinstated. He abdicated the throne for the second and last time in 1922, when Greece lost the Greco-Turkish War of 1919–1922, and was succeeded by his eldest son, George II. He died in exile four months later, in Sicily.