In May 1941, Clark formed and commanded "Habforce" (which when in Iraq became part of Iraqforce) which crossed the desert from Trans-Jordan to relieve RAF Habbaniya during the Anglo-Iraqi War. When "Kingcol", the flying column of "Habforce", arrived the airfield garrison had already forced the threatening Iraqi force to retire. With the arrival of "Kingcol" the garrison drove on to capture Falluja and "Kingcol" then exploited this to advance on Baghdad, arriving on 29 May. The Iraq government capitulated two days later.