Sayyid Hussein bin Ali, GCB (1854 — June 4, 1931) (حسین بن علی; Ḥusayn bin ‘Alī) was the Sharif of Mecca, and Emir of Mecca from 1908 until 1917, when he proclaimed himself King of Hejaz, which received international recognition. In 1924, he further proclaimed himself Caliph of all Muslims. He ruled Hejaz until 1924, when, defeated by Abdul Aziz al Saud, he abdicated the kingdom and other secular titles to his eldest son Ali.