Son of Ali and Fatima, grandson of the Prophet and third Imam in Shia tradition. Martyred at Karbala on 10 Muharram 61 AH (10 Oct 680), the day of Ashura, against Yazid's army. The shrine over his grave (Haram al-Husayni) is among the foremost pilgrimage centers of the Islamic world. (Sources: TDV 'Hüseyin'; WikiShia.)