When the old imam al-Mahdi Ibrahim was defeated and captured by the Rasulid sultan, the Zaidi elite of the northern Yemeni highland asked the ex-imam al-Hasan bin Wahhas to succeed.
[2] The strongest political figure in the Zaidi lands was, however, the emir Sarim ad-Din Da'ud, son of a former imam, who was the leader of the Hamzite Sharifs.
In 1284, Sarim ad-Din tried to induce al-Mutawakkil al-Mutahhar and al-Hasan bin Wahhas to enter hostilities with the Rasulid Dynasty, but they mistrusted him and refused.
Sarim ad-Din then made an abortive attempt to set up a close relative, Ahmad bin Ibrahim, as imam.
The imam was celebrated under the honorific al-Muzallal bi'l-Ghamama, since he was once miraculously saved by a cloud when he was pursued by Sultan al-Mu'ayyad Da'ud in Khawlan.