Al-Hadi Ali (1345/46 – September 6, 1432) was a claimant to the Zaidi state in Yemen, who posed as imam from 1393 to 1432 in rivalry with another prince.
[1] After the demise of imam an-Nasir Muhammad Salah ad-Din in 1391, a struggle broke out between his son al-Mansur Ali and another contender, al-Mahdi Ahmad bin Yahya.
During his almost 40 years long imamate he was generally overshadowed by al-Mansur Ali, who was celebrated as a mujaddid bi-sayfihi, a warlike restorer, and who died only in 1436.
However, the Rasulid army defeated his soldiers and drove them towards Wadi Juban, south of Ma'rib.
Al-Hasan's son in turn, al-Hadi Izz ad-din, held the Zaidi imamate in 1474–1495.