He belonged to the Qasimid family, descended from the Islamic prophet, Muhammad, which dominated the Zaidi imamate of Yemen from 1597 to 1962.
In the same year he undertook a military campaign to subdue the lowlands of Yemen, Tihamah, which had been lost for the Zaidi state since 1832.
[3] Imam Al-Mansur Ali had some initial successes and issued a proclamation from Qataba where he enjoined various chiefs to submit to Zaidi rule.
Eventually a relative called Muhammad bin Yahya claimed the imamate and appeared before San'a with an army of tribesmen in 1845.
However, the day after the arrival of the detachment to the city, it was furiously attacked by the locals, supposedly enjoined by the imam.
The Turkish commander Tefvik Pasha, who was badly wounded, immediately deposed al-Mutawakkil Muhammad and raised al-Mansur Ali to the imamate for the third time.
In June 1850 he was deposed for the third time by a rising headed by a distant relative called al-Mu'ayyad Abbas.
He continued to live in the vicinity of San'a, and in 1870 reportedly co-wrote a letter that invited the Porte back to end the chaos of the highlands.