"The two most significant decisions of the conference were to offer the throne of Iraq to Emir Faisal ibn Hussein (who became Faisal I of Iraq) and an emirate of Transjordan (now Jordan) to his brother Abdullah ibn Hussein (who became Abdullah I of Jordan). Transjordan was to be constituted as an Arab province of Palestine. The conference provided the political blueprint for British administration in both Iraq and Transjordan, and in offering these two regions to the sons of Sharif Husssein ibn Ali of the Hedjaz, Churchill believed that the spirit, if not the letter, of Britain's wartime promises to the Arabs might be fulfilled.

After further discussions between Churchill and Abdullah in Jerusalem, it was mutually agreed that Transjordan was accepted into the mandatory area with the proviso that it would be, initially for six months, under the nominal rule of the Emir Abdullah and would not form part of the Jewish national home to be established west of the River Jordan.[43] [44]

That agreement was formalized before the mandate officially went into effect. In September 1922, the British government presented a memorandum to the League of Nations stating that Transjordan would be excluded from all the provisions dealing with Jewish settlement, and this memorandum was approved on 23 September. A clause was added to the charter governing the Mandate for Palestine which allowed Great Britain to postpone or permanently withhold all of the provisions which related to the 'Jewish National Home' on lands which lay to the east of the Jordan River.[45][46]

From that point onwards, Britain administered the part west of the Jordan, 23% of the entire territory, as "Palestine", and the part east of the Jordan, 77% of the entire territory, as "Transjordan." Technically they remained one mandate but most official documents referred to them as if they were two separate mandates. Transfer of authority to an Arab government took place gradually in Transjordan, starting with the recognition of a local administration in 1923 and transfer of most administrative functions in 1928. Britain retained mandatory authority over the region until it became fully independent as the Hashemite Kingdom of Trans-Jordan in 1946."