1918: Faisal, the leader of the Arab revolt and the third son of Hussein, King of Hejaz, is declared head of a provisional government in what was previously the Vilayet of Syria The area which became Trans-Jordan was split between the southern extension of Syria and the northern extension of Hejaz
1921: In March, the Cairo Conference (1921) agrees to award the Emirate of Trans-Jordan to Abdullah and the mandate of Mesopotamia to Faisal During the conference, Winston Churchill invites Abdullah to a famous "tea party" where he convinced Abdullah to stay put and not attack the French in return for the creation of the Emirate of Transjordan.
1922: The Council of the League of Nations accepts the British Transjordan memorandum defining the limits of Trans-Jordan and excluding that territory from the provisions in the Mandate concerning the Jewish national home.
1922: British Government passes the Order defining Boundaries of Territory to which the Palestine Order-in-Council does not apply
1923: Britain recognises Transjordan with Abdullah as its leader
1925: Hadda Agreement between TransJordan and Nejd formally agrees the boundary between the two countries following the Kuwait Conference. The agreement concludes by stating "This Agreement will remain in force for so long as His Britannic Majesty's Government are entrusted with the Mandate for Trans-Jordan"
1965: Jordan and Saudi Arabia concluded a bilateral agreement that realigned and delimited the boundary, resulting in some exchange of territory, allowing Jordan to expand its port facilities at Aqaba and protecting the pasturage and watering rights of certain nomadic tribes.