Muqtada al-Sadr
Created by Muqtada al-Sadr and a small fraction of Shias, the Mahdi Army began as a group of roughly 500 seminary students connected with Muqtada al-Sadr in the Sadr City district of Baghdad, formerly known as Saddam City. The group moved in to fill the security vacuum in Sadr City and in a string of southern Iraqi cities following the fall of Baghdad to U.S-led coalition forces on April 9, 2003. The group was involved in dispensing aid to Iraqis and provided security in the Shi'ite slums from looters.