Caliph

The office of successor to Muhammad. The caliph was the political and spiritual leader of the Islamic world, originally legitimized by the consensus of the community. Unity was shattered by the mid-7th century and the office disputed by rival dynasties - the Umayyads and Abbasids, and from the 10th century the Fatimids in Egypt. By the end of the 10th century the Abbasid caliphs had lost political authority. Although the office survived until 1258 it became largely a titular position.