Muqtada Al-Sadr, the son of a prominent Shiite cleric assassinated in a 1999 attack believed to be organized by Iraqi dictator Saddam Hussein, quickly organized Shiite dispossessed under Saddam against the American occupation after the 2003 U.S.-led invasion.
Saddam loyalists and Shiite extremists alike would soon fight an insurgency against the American forces. Al-Sadr's Mahdi Army militia fought American forces throughout much of 2004 in Baghdad and other cities. Al-Sadr's forces are believed to have later taken part in the sectarian killings between Shiites and Sunnis that plagued Iraq for several years after the bombing of one of the holiest sites in Shiite Islam.
Since that time, much has changed.
Al-Sadr's followers have taken part in Iraqi military offensives against the Islamic State group in Tikrit and other cities. He has organized rallies against government corruption, including breaching the fortified Green Zone in Baghdad, the highly secure area housing government offices and many foreign embassies.
