Fatimid: Dynasty founded by Said ibn Husayn of Notheastern Syria, which claimed the Caliphate on the basis of descent from Fatima, daughter of Prophet Mohammad (PBUH). Around 893 a follower of Said ibn Husayn, went to Nothwest Africa and, with the support of the Berbers, won Tunisia, Sicily, Northern Algeria, and North Libya for the Fatimids. Said ibn Husayn was then hailed as the Mahdi. In the reign (953-75) of the fourth caliph, Moizz, the Fatimids conquered Egypt, Palestine, parts of Syria, and Western Arabia. In 973 Moizz moved his capital to the new city of Cairo. Reliance on mercenaries, religious intolerance, and losses to the Normans and Crusaders in the 11th cent. led to the decline of the Fatimids, who were succeeded in their last stronghold, Egypt, by the rival Abbasids in 1171.