The British involvement in Iraq and Persia (Iran) during the Second World War was heavily dependent on the availability of formations and units from the British Indian Army. Without them, it is unlikely that the U.K. government could have prevented increased German and Italian influence in Iraq and the consequent threat to oil supplies.

The first formation to land at Basra was the 10 Indian Infantry Division, which was followed by the 8 Indian and 6 Indian Infantry Divisions. Together, these three formations seized control of Iraq, and then Persia (Iran), and elements also participated in the invasion of Syria. The 5 Indian Infantry Division was sent to Iraq to rebuild after suffering heavy losses in Egypt in mid-1942. It left after a short period of time to return to India.

The 2 and 12 Indian Infantry Divisions were static formations, designated as ‘divisions’ for deception purposes, to make the strength of British forces in Persia and Iraq appear stronger than they actually were.

The 2 Indian Infantry Division was a pre-war formation in the Indian Army. It was a static formation based in India, however, it had been disbanded prior to September 1939. The 2 Indian Division was reformed in August 1942, with its headquarters at Baghdad. The headquarters were formed by Headquarters, Iraq Area, and had formerly been known as Persia & Iraq Base & Lines of Communication Area. The designation as a ‘division’ was for deception purposes. There was no commander, the headquarters being the responsibility of the Deputy Quarter-Master-General, Base & Lines of Communication. In May 1943, the H.Q. 31 Infantry Brigade were redesignated as the H.Q. 2 Indian Infantry Division and the Kermanshah Sub-Area became the 31 Indian Infantry Brigade. In October 1944, it was redesignated as the Northern Iraq Area.

The 5 Indian Infantry Division was raised in India and sailed for the Middle East in late 1940. The division fought in the Western Desert from May 1942 to September 1942, losing the 10 Indian Infantry Brigade and 29 Indian Infantry Brigade, both of which were destroyed as formations. With only the 9 Indian Infantry Brigade under command, the division moved to Iraq to refit. It arrived in October 1942, where it was joined by the 7 Armoured Brigade and the 161 Indian Infantry Brigade. The division was under command of PaiForce, being stationed near Baghdad. It trained as a mixed division, but in May 1943, the division was ordered back to India. As an armoured brigade was not required in the Far East, the 7 Armoured Brigade remained in the Middle East as an independent formation. The division began arriving at Bombay in June 1943.

The 6 Indian infantry Division was formed in India and then sent to Iraq. The divisional headquarters arrived in Basra on the 11 September 1941. The division moved into Persia to be stationed in and around the Kermanshah area. The role of the division was guard duties, preparation of defensive positions and internal security. In February 1942, it moved to Sar-i-Pul Zuhab under command of 10 Army. In September that year, it moved to the Sultanabad area under command of XXI Indian Corps. From April 1943 onwards, the division was employed on railway and pipeline protection duties in the area of Kermanshah, Hamadan and Qizil Rabat. In early 1944, provisional plans were made for the division to be sent to Italy, and training commenced. However, the move was cancelled, and with the threat to Iraq and Persia having declined, the division was broken up in September and October 1944. The divisional headquarters ceased to function on 15 October 1944 at Basra.