Hussein was the namesake of his paternal great-grandfather, Hussein bin Ali (Sharif of Mecca), the leader of the 1916 Arab Revolt against the Ottoman Empire. Hussein claimed to be an agnatic descendant of Muhammad's daughter Fatimah and her husband Ali, the fourth caliph, since Hussein belonged to the Hashemite family, which had ruled Mecca for over 700 yearsuntil its 1925 conquest by the House of Saudand has ruled Jordan since 1921. The Hashemites, the oldest ruling dynasty in the Muslim world, are the second-oldest-ruling dynasty in the world (after the Imperial House of Japan).