Fāṭimids, a dynasty that rose to political dominion in North Africa in 297/909 after a long period of secret revolutionary activity in various regions of the Islamic world. They formally proclaimed their caliphate in Rabīʿ II 297/January 910. The new caliph, al-Mahdī, was already imam of the Shiʿi Ismailis but, until then, he had not actually ruled a politically defined territory. However, he and his success…