The Mourning of Muharram , also known as the Muharram observances, is a set of commemoration rituals observed primarily by Shia Muslims. The commemoration falls in Muharram, the first month of the Islamic calendar. Many of the events associated with the ritual take place in congregation halls known as Hussainia or Imambargah.The event marks the anniversary of the Battle of Karbala (AD 680/AH 61), when Imam Hussain ibn Ali, a grandson of Prophet Muhammad, was martyred by the forces of Ubayd Allah ibn Ziyad, on the orders of Yazid I. Family members and companions accompanying him were either killed or subjected to humiliation.