Sultanates The Abbasid state became weaker from the ninth century because Baghdad’s control over the distant provinces declined, and because of conflict between pro-Arab and pro-Iranian factions in the army and bureaucracy. In , a civil war broke out between supporters of Amin and Mamun, sons of the caliph Harun al-Rashid, which deepened the factionalism and created a new power bloc of Turkish slave officers ( mamluk ). Shiism once again competed with Sunni orthodoxy for power. A number of minor dynasties arose, such as the Tahirids and Samanids in Khurasan and Transoxiana (Turan or lands beyond the Oxus), and the Tulunids in Egypt and Syria.
Abbasid power was soon limited to central Iraq and western Iran. That too was lost in when the Buyids, a Shiite clan from the Caspian region of Iran (Daylam), captured Baghdad. The Buyid rulers assumed various titles, including the ancient Iranian title shahanshah (king of kings), but not that of caliph. They kept the Abbasid caliph as the symbolic head of their Sunni subjects.
The decision not to abolish the caliphate was a shrewd one, because another Shiite dynasty, the Fatimids, had ambitions to rule the Islamic world. The Fatimids belonged to the Ismaili sub-sect of Shiism and claimed to be descended from the Prophet’s daughter, Fatima, and hence, the sole rightful rulers of Islam. From their base in North Africa, they conquered Egypt in and established the Fatimid caliphate. The old capital of Egypt, Fustat, was replaced by a new city, Qahira (Cairo), founded on the day of the rise of the planet Mars ( Mirrikh , also called al-Qahir ).
The two rival dynasties patronised Shiite administrators, poets and scholars. Between and , Islamic society was held together not by a single political order or a single language of culture (Arabic) but by common economic and cultural patterns. Unity in the face of political divisions was maintained by the separation between state and society, the development of Persian as a language of Islamic high culture, and the maturity of the dialogue between intellectual traditions. Scholars, artists and merchants moved