person - (who-SAYN) (626 - 680) son of Ali, whom the Shi'a believe should have succeeded him as Caliph. That position went instead to Muawiyah. When Muawiyah died in 680, Hussein attempted to claim the Caliphate, but the position went to Muawiyah's son Yazid. Hussein then set out with troops to lead an insurrection, but was killed in the battle of Kerbala on 10th Muharram 61 / October 680.