Demographics of Iraq
97% of Iraqis follow Islam: 61% Shia and 34% Sunni. 1% of these describe themselves as "Just a Muslim". According to the CIA Factbook, Shias make up 60% of population, while Sunnis 35%. Christianity accounts for 5%, and the rest practice Mandaeism, Yazidism and other religions.
Shia–Sunni relations
The Shias openly revolted against Saddam following the Gulf War in 1991 and were encouraged by Saddam's defeat in Kuwait and by simultaneous Kurdish uprising in the north. However, Shia opposition to the government was brutally suppressed, resulting in some 50,000 to 100,000 casualties and successive repression by Saddam's forces. The governing regimes of Iraq were composed mainly of Sunnis for nearly a century until the 2003 Iraq War.