During World War I, the British and French divided Western Asia in the Sykes-Picot Agreement. The Treaty of Sèvres (which did not enter into force), and the Treaty of Lausanne which superseded the former, led to the advent of modern Western Asia and the modern Republic of Turkey. The League of Nations granted France mandates over Syria and Lebanon and granted the United Kingdom mandates over Palestine (which then consisted of two autonomous regions: Mandatory Palestine and Transjordan) and what was to become Iraq. Parts of the Ottoman Empire on the Arabian Peninsula were eventually overtaken by Saudi Arabia and Yemen.
On December 1, 1918, during a meeting in Sulaymaniyah with Colonel Arnold Wilson, the Acting Civil Commissioner for Mesopotamia, Kurdish leaders called for British support for a united and independent Kurdistan under British protection. Between 1919 and 1922, Shaikh Mahmud Barzanji, an influential Kurdish leader based in Sulaymaniyah, formed a Kurdish government and ledtwo revolts against the British rule. It took the British authorities until 1924 to put down his uprisings. The first revolt began on May 22, 1919 with the arrest of British officials in Sulaymaniyah and it quickly spread to Mosul and Arbil. The British employed aerial bombardments, artillery, ground attacks by Anglo-Indiantroops and Assyrian Levies, and on one occasion, chemical gas, in an attempt to quell the uprising. Then, with the collapse of the Kurdish forces the British exiled Mahmud Barzanji to India. In July 1920, 62 tribal leaders of the region called for the independence of Kurdistan under a British mandate. The objection of the British to Kurdish self-rule sprang from the fear that success of an independent Kurdish area would tempt the two Arab areas of Baghdad and Basra to follow suit, hence endangering the direct British control over all Mesopotamia. In 1922, Britain restored Shaikh Mahmud to power, hoping that he would organize the Kurds to act as a buffer against the Turks, who had territorial claims over Mosul and Kirkuk. However, defiant to the British, in 1922 Shaikh Mahmoud declared a Kurdish Kingdom with himself as king. It took two years to the British to bring Kurdish areas into submission, while Shaykh Mahmud found refuge in an unknown location. In 1930, following the announcement of the admission of Iraq to the League of Nations, Shaikh Mahmoud started a third uprising which was suppressed with British air and ground forces.
By 1927, the Barzani clan had become vocal supporters of Kurdish rights in Iraq. In 1929, the Barzani demanded the formation of a Kurdish province in northern Iraq. Emboldened by these demands, in 1931 Kurdish notables petitioned the League of Nations to set up an independent Kurdish government. In late 1931, Ahmed Barzani initiated a Kurdish rebellionagainst Iraq, and though defeated within several months, the movement gained a major importance in the Kurdish struggle later on, creating the ground for such a notable Kurdish rebel as Mustafa Barzani. During WWII, the power vacuum in Iraq was exploited by the Kurdish tribes and under the leadership of Mustafa Barzani a rebellion broke out in the north, effectively gaining control of Kurdish areas until 1945, when Iraqis could once again subdue the Kurds with British support. Under pressure from the Iraqi government and the British, the most influential leader of the clan, Mustafa Barzani was forced into exile in Iran in 1945. Later he moved to the Soviet Union after the collapse of theRepublic of Mahabad in 1946