The city of Karbala contains the most important Shi’i religious shrine in the world. It is the tomb of Hussein ibn Ali Abu Talib. He was the grandson of the Prophet Muhammad and the son of Ali, the forth caliph of Islam. He and more than 70 of his followers were murdered in 680 by troops of the Umayyad caliph of Damascus.

Shi’i Muslims make pilgrimage to Karbala twice each year. The first pilgrimage is on the tenth day of the Islamic month of Muharram, the date of Hussein’s martyrdom. The second pilgrimage occurs forty days later at the end of the official mourning period making his death. Since the ouster of Saddam Hussein, between one million and two million Shi’i Muslims have made the pilgrimage each year. A large number of pilgrims travel to the site from Iran, a nation with a Shi’a majority.