An ethnic Turkmen born in Tel Afar, Nineveh Province, al-Hiyali was an Iraqi Army Colonel under Saddam Hussein.[1][3][4] According to documents discovered in Iraq, al-Hiyali was a lieutenant colonel in the Iraqi military's intelligence unit Istikhbarat (Directorate of General Military Intelligence), who also spent time as a Special Forces officer in the Special Republican Guard right up until the US-led 2003 invasion of Iraq.[5][6] He was decommissioned from the Iraqi army after U.S. forces arrived, and joined Sunni insurgents to fight the Americans.[3] Like other ISIL leaders, Abu Muslim Al Turkmani spent time in a US prison in Iraq, specifically Camp Bucca.[7][8] He once practiced a moderate form of Islam.[3]