At the St Remo Conference Britain was assigned Palestine, Transjordan, and an oil-rich area, renamed Iraq, consisting of
lower Mesopotamia and a part of Upper Mesopotamia. To ensure the control of Haifa, needed as a fuelling post for her oil-fired navy ships, Britain agreed to accept responsibility for Palestine from Gath to Beersheba.
Britain also consented to use the administration to be set up in Palestine to administer Transjordan as well, as allowed by article 22 in The Covenant of the League of Nations: i.e.
Certain territories, which, owing to the sparseness of their population, or their small size, or their remoteness from the centres of civilisation, or their geographical contiguity to the territory of the Mandatory, can be best administered under the laws of the Mandatory as integral portions of its territory, subject to the safeguards above mentioned in the interests of the indigenous population.
After the St Remo conference the Muslim-Christian Associations joined to hold the first Palestine Arab Congress in Jerusalem. Its main platforms were a call for representative government and opposition to the Balfour Declaration.
Although the Ottoman Sultan signed a treaty at Sèvres in which he renounced all rights over Arab Asia,
the treaty could not come into force until the Turkish Senate had ratified it. However, the Turkish Senate at first refused to ratify the treaty and did not do so until 1923.
Although the mandate was not yet a legal instrument, in June 1920, the British transferred Palestine from military administration to civil administration and appointed Viscount Herbert Louis Samuel as High Commissioner. Soon afterwards, under pressure from Zionists, Britain negotiated with France to swap part of the Golan Heights, originally apportioned to British Palestine, for the Jewish settlements in north Galilee which had up to then been part of French administered Syria. However, in addition to the Jewish settlements, this brought a number of Shia Muslim villages into British administered Palestine although most Palestinian Muslims were Sunni. This created another source of friction in Palestine.
Katika Mkutano wa St. Remo, Uingereza ilipewa Palestina, Transjordan, na eneo lenye mafuta mengi, lililoitwa tena Iraq, ambalo lilikuwa Mesopotamia ya chini na sehemu ya Mesopotamia ya Juu. Ili kuhakikisha udhibiti wa Haifa, iliyohitajika kama kituo cha mafuta kwa meli zake za majini zilizotumia mafuta, Uingereza ilikubali kukubali kuwa na jukumu la Palestina kutoka Gathi hadi Beersheba. Uingereza pia ilikubali kutumia utawala uliowekwa katika Palestina kusimamia Transjordan pia, kama ilivyoruhusiwa na kifungu cha 22 katika Mkataba wa Jumuiya ya Mataifa. """Maeneo fulani ambayo kwa sababu ya idadi ndogo ya watu, au ukubwa wao mdogo, au umbali wao kutoka kwa vituo vya ustaarabu, au ukaribu wao wa kijiografia na eneo la Mandatory, yanaweza kusimamiwa vizuri chini ya sheria za Mandatory kama sehemu muhimu ya eneo lake, chini ya ulinzi uliotajwa hapo juu kwa maslahi ya wenyeji." Baada ya mkutano wa St Remo Mashirika ya Kiislamu na Kikristo yaliungana kufanya Mkutano wa kwanza wa Kiarabu wa Palestina huko Yerusalemu. Maandamano yake makuu yalikuwa wito wa serikali ya uwakilishi na upinzani kwa Azimio la Balfour. Hata hivyo, baada ya Sultani wa Ottoman kusaini mkataba huko Sevres, alikataa haki zake zote juu ya Asia ya Kiarabu, na mkataba huo haukuweza kuanza kutumika mpaka Seneti ya Uturuki ikiridhia. Hata hivyo, Seneti ya Uturuki ilikataa kuidhinisha mkataba huo na haikufanya hivyo hadi mwaka wa 1923. Hata hivyo, baada ya kuidhinishwa kwa amri hiyo, Uingereza ilihamisha Palestina kutoka kwa utawala wa kijeshi hadi utawala wa kiraia na kumteua Herbert Louis Samuel kuwa Kamishna Mkuu. Muda mfupi baadaye, chini ya shinikizo la Wasionisti, Uingereza ilifanya mazungumzo na Ufaransa kubadilishana sehemu ya Milima ya Golan, ambayo awali iligawanywa kwa Palestina ya Uingereza, kwa makazi ya Kiyahudi kaskazini mwa Galilaya ambayo hadi wakati huo ilikuwa sehemu ya Syria iliyodhibitiwa na Ufaransa. Hata hivyo, pamoja na makazi ya Kiyahudi, hii ilileta vijiji kadhaa vya Waislamu wa Shia katika Palestina iliyodhibitiwa na Waingereza ingawa Waislamu wengi wa Palestina walikuwa Wasunni. Jambo hilo lilitokeza mzozo mwingine huko Palestina.