عبيد الله بن زياد
The event marks the anniversary of the Battle of Karbala (AD 680/AH 61), when Imam Hussein ibn Ali, a grandson of Prophet Muhammad, was martyred by the forces of Ubayd Allah ibn Ziyad. Family members and companions accompanying him were either killed or subjected to humiliation. The commemoration of this event during the yearly mourning season, with the Day of Ashura as the focal date, serves to define Shia communal identity. Muharram observances are carried out in countries with a sizable Shia population.