The assassination of Caliph ′Ali in the Iraqi city of Kufa and of Imam Husayn, the grandson of the Prophet, at Karbala, gave rise to Shi‘ism. The movement claimed its right to the caliphate based on its leaders’ descent from Muhammad. Fiercely attacked by the Umayyads and Abbasids, Shi‘ism nevertheless continued to spread throughout the Muslim world and soon reached North Africa. It was here that the Shi‘ite Muslims, led by Abu ‘Abdallah al-Shi‘i, decided to establish themselves with a view to conquering the Islamic caliphate.
The Fatimid caliphate was effectively born at Raqqada in Ifriqiya (modern Tunisia), and from there the movement succeeded in overthrowing the local Aghlabid dynasty in AH 297 / AD 909. The first Fatimid capital was al-Mahdiyya, the urban and architectural fabric of which carried their mark. Under the enlightened rule of the Fatimid Caliph al-Mu‘izz li-Din Allah (r. 341–63 / 953–75) the realm became remarkably prosperous, and the economic conditions provided a favourable climate in which to attempt the conquest of the caliphate. As part of his plan to achieve this objective he dispatched General Jawhar to conquer Egypt, which had suffered much under Tulunid rule. In 357 / 969 al-Mu‘izz entered Egypt victorious, delegating the rule of North Africa to his Zirid vassals. The Zirids saw the opportunity to become independent and renounce Shi‘ism in favour of Sunni Islam, a move that was punished by the Fatimids, who promptly deployed the barbarian Bedouin tribe, the Banu Hilal, to devastate their lands. Fatimid power now shifted to Egypt and in 357 / 969 al-Mu‘izz founded a new capital, Cairo. Based on an ever-expanding empire, a brilliant civilisation evolved, rivalling that of the Abbasids in Baghdad and the Umayyads in Spain. Urbanism, the sciences, art and literature reached new heights. However, these achievements were not to last: the arrival of the Crusaders, economic decline and major epidemics all contributed to the fall of this brilliant dynasty, which was eventually extinguished at the hands of Salah al-Din Ayyubi (Saladin) in 567 / 1171.