Shia is the majority religion of both Iran and Iraq. A Sunni Muslim, Saddam Hussein severely restricted pilgrimages from Iran. Iranian visitors could only make arrangements through special travel agencies and while in the holy cities, were always under the intense scrutiny of Saddam's security Services. Visitors could only stay for three days. Pilgrimages were not permitted during the Iran-Iraq War from 1980-8. Iran closed its border with Iraq in March 2003 with the onset of U.S. forces, but reopened it in September 2003 to reduce illegal crossings.

The city of Karbala was against the secular, Baathist rule of Saddam Hussein. During his regime, a number of clerics from the city were murdered. Saddam put his own pictures on the shrines (he also claimed to be descended from Muhamed).

Karbala is alleged as the site where Imam Hussein was killed. In 680 Imam Hussein challenged the leadership of Yazid Mu'awiyah who succeeded his father as caliph. Hussein refused to offer allegiance based on Yazid's neglect of the principles of Islam. Yazid sent his troops to suppress the spiritual leader. The smaller forces of Imam Hussein were surrounded in Karbala, and he and his brother Abbas were killed.