Al-Hadi Yahya was an imam of part of the Zaidi state in Yemen.
Najm ad-Din Yahya bin Muhsin was a seventh-generation descendant of imam al-Mukhtar al-Qasim (d.
[1] The old imam al-Mansur Abdallah died in 1217 in Kawkaban after many years of inconclusive struggles against the Ayyubids, who established a sub-branch in Yemen in 1173.
The first Rasulid Sultan, Nur ad-Din Umar I, seized several places in the highland, such as San'a, Ta'izz and Kawkaban.
His death was followed by an interregnum of nine years until al-Mahdi Ahmad bin al-Husayn, from another branch of the Rassids, was proclaimed.