Abu'l-Qasim al-Tayyib

Abū'l-Qāsim al-Ṭayyib ibn al-Āmir was, according to the Tayyibi sect of Isma'ilism, the twenty-first imam. The only son of Caliph al-Amir bi-Ahkam Allah, al-Tayyib was an infant when his father was murdered. Amidst the ensuing power struggle, al-Tayyib disappeared; modern historians suggest that he died or was secretly killed by one of the rival strongmen. By 1132, his uncle al-Hafiz declared himself as the caliph and imam in succession to al-Amir. This was not accepted by the Yemeni Isma'ilis, who upheld the rights of al-Tayyib.