The station was a large flying training school during the Second World War, as well as a transport staging airfield. During the Rashid Ali rebellion in 1941, the airfield was besieged by units from the Royal Iraqi Army encamped on the overlooking plateau. On 2 May 1941, British forces from the airfield launched pre-emptive airstrikes on Iraqi forces throughout Iraq and the Anglo-Iraqi War began. The siege was lifted by the units based at Habbaniya, including pilots from the training school, a battalion of the King's Own Royal Regiment flown in at the last moment, Number 1 Armoured Car Company RAF and the RAF's Iraq Levies. The subsequent arrival of a relief column ("Kingcol"), part of "Habforce" sent from Palestine, then a British mandate, combined with the Habbaniya units to force the rebel forces to retreat to Baghdad.