1941 Iraqi coup d ' état The 1941 Iraqi coup d ' état , also known as the Rashid Ali Al - Gaylani coup or the Golden Square coup , was a pro - Nazi military coup in Iraq on April 1 , 1941 that overthrew the regime of Regent ' Abd al - Ilah and installed Rashid Ali as Prime Minister . It was led by four Iraqi nationalist army generals , known as " the Golden Square . " The Golden Square intended to use the war to press for full Iraqi independence following the limited independence granted in 1932 . To that end , they worked with German intelligence and accepted military assistance from Germany . The change in government led to a British invasion of Iraq and subsequent occupation until 1947 . The coup . From 1939 to 1941 , Iraq was ruled by a pro - British government headed by the Regent ' Abd al - Ilah and Prime Minister Nuri as - Said . Iraq had severed relations with Germany on September 5 , 1939 , following the outbreak of World War II in Europe . However , Nuri had to tread carefully between his close relationship with Britain and dependence on pro - German Army officers and cabinet members . By that time , Iraq became a refuge to Arab leaders who fled Mandate Palestine as a result of failed Arab revolt against the British . Among the key figures to arrive was the Grand Mufti of Jerusalem - Mohammad Amin al - Husayni , the Arab nationalistic leader of the failed revolt . The Golden Square coup was initiated on April 1 , 1941 , overthrowing the regime of Regent ' Abd al - Ilah and installing Rashid Ali as Prime Minister . The Mufti Amin al - Husayni was one of the orchestrators of Rashid Ali al - Gaylani ' s coup d ' état , with Nazi support and financing . British response . British forces sent to quell the revolt . On 18 April , Britain reacted by landing the Indian 20th Infantry Brigade at Basra , the first elements of Iraqforce . Britain claimed it was entitled to do this under its defense treaty with Iraq . This treaty was essentially dictated by the British without negotiation or agreement before independence was granted to Iraq . It gave the British unlimited rights to station and transit troops through Iraq without consulting the Iraqi government . Siege of Habbaniya . In the following days , the new Iraqi government moved substantial ground forces , including an infantry brigade , an artillery brigade , and 12 armored cars as well as tanks to the plateau overlooking the large British Royal Air Force ( RAF ) base at Habbaniya , 50 miles west of Baghdad on the Euphrates River . Upon arrival , the Iraqis demanded that the British not move any troops nor aircraft in or out of the base . The British responded by first demanding that the Iraqis leave the area and then , following the expiration of an ultimatum given in the early hours of May 2 , launched an attack . The base had immediately available a force of 96 mostly obsolete aircraft , most of which were used for training . They also had an understrength battalion from the King ' s Own Royal Regiment ( Lancaster ) , six companies of levies ( Iraqi troops raised by the British ) , 18 armored cars and a company of RAF personnel , giving a total strength of 2 , 200 troops to defend the base . The Iraqi air force , which included a number of modern German - and Italian - built machines , proved to be no match for the RAF . By the second day of fighting ( May 3 ) , 4 more Blenheim fighter bombers arrived . With British forces having dominant air superiority , the Iraqis were forced back to Falluja and the air battle was taken to the remaining Iraqi Air Force bases at Mosul and Rashid ; Habbaniya had essentially lifted the siege upon its resources . Reinforcements , in what became known as " Iraqforce " , came from two directions . British , Transjordanian , and Arab Legion forces arrived in two columns ( " Habforce " and " Kingcol " ) across the desert from the Transjordan . Additional Indian forces continued to arrive in Basra . The Iraqi army was driven out of Falluja and pursued to Baghdad , which fell within a week . This cleared the way for the nominal restoration of the Regent and the pro - British government . British military occupation of Iraq continued until late 1947 . Axis support for the nationalists . During the course of the Iraq war , minor reinforcements for the nationalists were received from both Germany and Italy . Arriving aircraft were crudely painted with Iraqi colours . A few aircraft from the German Air Force ( " Luftwaffe " ) flew sorties from Mosul against both the base at Habbaniya and the relieving Commonwealth forces moving across from Transjordan . This was done to little effect . However , the Vichy French authorities in the Syrian Mandate had given some assistance to both the pro - Axis Iraqi nationalists and to the Germans ( providing staging bases for the aircraft of the German Air Force ) . Even before the end of the Iraq campaign , this had led to RAF attacks on airbases in Syria . The Vichy assistance to the Axis and the British air attacks in response would lead to the full - scale invasion of Vichy - occupied Syria and Lebanon within weeks during the Syria - Lebanon campaign .