Shia Muslims watch a reenactment of the centuries-old battle of Karbala during which Imam Hussein, grandson of Islam’s founding prophet, Muhammad, was slain, as part of Ashura commemorations on Jan. 31, 2007, in Qatif, Saudi Arabia. Banners on the walls praise Hussein. (AP Photo/Hasan Jamali)

The Shia rejected the authority of the Umayyad dynasty, claiming that the Umayyads were usurpers and demanding that leadership go to the direct descendants of the Prophet. The Shia rose in the city of al-Kufah (south of Karbala, in present-day Iraq) and, in 680 A.D., invited Ali’s son Hussein to join them and be their leader. Hussein left Mecca with his family and supporters, but was met at Karbala by an army sent by the Umayyad caliph Yazid. Hussein mustered 72 fighting men against the opposing force of thousands. The result was a massacre in which Hussein and all of his family and supporters were killed and then mutilated.

In observance of the massacre, Sunni and Shia alike regard the 10th day of the month of Muharram as “Ashura,” a day of mourning. For the Sunni the day is merely an optionally observed fast, but for the Shia, it is among the most significant days of observance. The massacre of Hussein added a significant passion element to the Shia tradition, similar to the Christian reverence for Christ’s passion on the cross. Hussein, to the Shia, is a martyr of resistance in the face of oppression, while Yazid represents that oppression. As an often-persecuted minority throughout history, the Shia made these concepts central to their tradition.

Ashura is marked with passion plays and public expressions of grief. All Shia who are capable are expected to make a pilgrimage to Karbala, where Hussein is buried, at some point in their lives to mark the day of Ashura.