Abū ʿAbd Allāh al-Shīʿī, al-Ḥusayn b. Aḥmad b. Muḥammad b. Zakariyyāʾ (d. 298/911), Ismaili dāʿī (summoner) and founder of the Fāṭimid caliphate in North Africa. Abū ʿAbd Allāh became associated with the Ismailis in the second half of the 3rd/9th century when Ibn Ḥawshab, the dāʿī of Yemen, sent him to the Maghrib. There, over a period of fifteen years, he gained such political strength and following that, with the help of the Kutāma Berbers, he was able to overthrow the dynasties of the Aghlabids, the Banū Midrār and Rustamids of Tāhart, and to lay the foundations of the Fāṭimid caliphate.

The…