The Imamate That Gave a School Its Shape

Zaidiyyah traces its name to Zayd ibn Ali, a grandson of Husayn ibn Ali, who led an unsuccessful revolt against Umayyad rule in Kufa in 740 and was killed in the fighting. His followers held a distinctive position within the wider Shia movement: that leadership belonged to any qualified descendant of Ali and Fatima who was willing to rise publicly in a rightful cause, rather than to a fixed line of divinely appointed and religiously infallible Imams as later Twelver Shia doctrine came to teach. That openness to a qualifying rather than a purely hereditary claim is part of why Zaidi legal method developed closer to Sunni practice than Twelver jurisprudence did, giving substantial weight to a jurist's own reasoned effort rather than resting rulings primarily on the transmitted sayings of a closed line of Imams.

The school's lasting legal shape came from al-Hadi ila'l-Haqq Yahya ibn al-Husayn, a descendant of Zayd who traveled to the Yemeni highlands at the invitation of feuding local tribes and, arriving in the town of Sa'dah in 897, established both a functioning Imamate and the body of legal teaching, later called the Hadawi school after him, that Zaidi communities in Yemen have followed since. Unlike Zayd's own failed rising, al-Hadi's state endured, giving Zaidi jurisprudence a territorial base its doctrine had not previously had.