HADI, AL-

died 786 in full al Hadi Ila al Haqq, also called Musa al-Hadi fourth caliph of the 'Abbasid dynasty (reigned 785786). Al-Hadi's persecution of the 'Alids, representatives of the Shi'ite sect of Islam, precipitated revolts in Medina, Egypt, and Iraq, all of which were put down brutally. Throughout his short reign, he struggled with the question of succession, attempting to annul the rights of his brother, Harun ar-Rashid, who was later to become one of the most famous rulers of the 'Abbasid dynasty. At the time of al-Hadi's death, which may have been a murder, ar-Rashid was imprisoned and then later was released to assume the caliphate.