Al-Mansur al-Qasim al-Iyyani

Al-Qasim bin Ali was a Sayyid from Tarj in the Khath'am region (present-day south-western Saudi Arabia).

He was a great-great-grandson of al-Qasim al-Rassi (d. 860), a key figure in the emerging of the Zaydiyyah brand of Shi'a Islam.

After the death of the Zaidi imam an-Nasir Ahmad in 934, political conditions had been unstable in the Zaydiyyah influenced areas.

One of his adherents composed a poem which emphasised the enthusiastic response among the tribesmen, and the role of the imam as a restorer: "Rise and lead the people, and send them with justice; remove darkness and ignorance from them.

After his failure to subdue the recalcitrant tribesmen of Banu Harith in Najran, he faced opposition from al-Malih Ibrahim and the former imam ad-Da'i Yusuf.

As a religious scholar, he followed al-Qasim ar-Rassi and al-Hadi ila'l-Haqq Yahya in the essentials, although he was also accused of theological deviations.