The Kingdom of Iraq under British Administration, or Mandatory Iraq (Arabic: الانتداب البريطاني على العراق, romanized: al-Intidāb al-Brīṭānī ʿalā l-ʿIrāq), was created in 1921, following the 1920 Iraqi Revolution against the proposed British Mandate of Mesopotamia, and enacted via the 1922 Anglo-Iraqi Treaty and a 1924 undertaking by the United Kingdom to the League of Nations to fulfil the role as Mandatory Power.

[1][2] Faisal ibn Husayn, who had been proclaimed King of Syria by a Syrian National Congress in Damascus in March 1920, was ejected by the French in July of the same year.

[3] The civil government of postwar Iraq was headed originally by the High Commissioner, Sir Percy Cox, and his deputy, Colonel Arnold Wilson.

The 1920 rebellion brought these groups together, if only briefly; this constituted an important first step in the long and arduous process of forging a nation-state out of Iraq's conflict-ridden social structure.

"[8] When the Kurdish leader Sheikh Mahmud launched an armed rebellion, the British used the newly established Iraqi army to suppress the revolt, but that proved ineffective.

[10] At the Cairo Conference of March 1921, the British set the parameters for Iraqi political life that were to continue until the 1958 revolution; they chose a Hashemite, Faisal ibn Husayn, son of Sherif Hussein ibn Ali former Sharif of Mecca as Iraq's first King; they established an Iraqi army (but kept Iraq Levies under direct British command); and they proposed a new treaty.

The British saw in Faisal a leader who possessed sufficient nationalist and Islamic credentials to have broad appeal, but who also was vulnerable enough to remain dependent on their support.

Faisal was instated as the Monarch of Iraq after the Naquib of Baghdad was disqualified as being too old (80 yrs) and Sayid Talib (a prominent Iraqi from the province of Basra) was deported on trumped up charges by the British.

Recognizing that the monarchy depended on British support— and wishing to avoid a repetition of his experience in Syria – Faisal maintained a moderate approach in dealing with the UK.

British obligations under the new treaty included providing various kinds of aid, notably military assistance, and proposing Iraq for membership in the League of Nations at the earliest moment.

[citation needed] Thus, while Iraq's body politic crumbled under immense political and economic pressure throughout the monarchic period, the military gained increasing power and influence; moreover, because the officers in the new army were by necessity Sunnis who had served under the Ottomans, while the lower ranks were predominantly filled by Shia tribal elements, Sunni dominance in the military was preserved.

The Anglo-Iraqi Treaty of 1930 provided for a "close alliance," for "full and frank consultations between the two countries in all matters of foreign policy," and for mutual assistance in case of war.

Because Iraq's newly established political institutions were the creation of a foreign power, and because the concept of democratic government had no precedent in Iraqi history, the politicians in Baghdad lacked legitimacy and never developed deeply rooted constituencies.

The absence of broadly based political institutions inhibited the early nationalist movement's ability to make deep inroads into Iraq's diverse social structure.

These were suppressed by the Iraqi government with assistance from the RAF Iraq Command, with Kedourie writing that the "killing, it seems, was indiscriminate, and old men, women and children were the victims."

[14]Kedourie's judgement, however, is different: When we consider the long experience of Britain in the government of Eastern countries, and set beside it the miserable polity which she bestowed on the populations of Mesopotamia, we are seized with rue- ful wonder.

It is as though India and Egypt had never existed, as though Lord Cornwallis, Munro and Metcalf, John and Henry Lawrence, Milner and Cromer had attempted in vain to bring order, justice and security to the East, as though Burke and Macaulay, Bentham and James Mill had never addressed their intelligence to the problems and prospects of oriental government.

[19] Before the collapse of the Ottoman Empire, the British-controlled Turkish Petroleum Company (TPC) had held concessionary rights to the Mosul wilaya (province).

The major obstacle was Iraq's insistence on a 20 percent equity participation in the company; this figure had been included in the original TPC concession to the Turks and had been agreed upon at Sanremo for the Iraqis.