In their capacity as Caliphs, the Sultans of the Ottoman Empire would appoint an official known as the Sharif of Mecca. The role went to a member of the Hashemite family, but the Sultans typically promoted Hashemite inter-familial rivalries in their choice, preventing the building of a solid base of power in the Sharif. With the outbreak of the First World War in 1914, the Sultan, in his capacity as Caliph, declared a jihad against the Entente powers. The British in particular hoped to co-opt the Sharif as a weighty alternative religious figure backing them in the conflict. The British already had a series of treaties with other Arab leaders in the region and were also fearful that the Hejaz could be used as a base to attack their shipping to and from India. The Sharif was cautious but, after discovering that the Ottomans planned to remove and possibly murder him, agreed to work with the British if they would support a wider Arab revolt and the establishment of an independent Arab kingdom the British implied they would. After the Ottomans executed other Arab nationalist leaders in Damascus and Beirut, the Hejaz rose against and soundly defeated them, almost completely expelling them. In 1916, the Sharif of Mecca Hussein bin Ali declared himself King of Hejaz as his Sharifian Army participated with other Arab forces and the British Empire in expelling the Turks from the Arabian peninsula. The US State Department quotes an aide-mémoire dated 24 October 1917 given by the Arab Bureau to the American Diplomatic Agency in Cairo confirming that The British, though, were compromised by their agreement to give the French control of Syria and did not, in Hussein's eyes, honour their commitments. Nevertheless, they did eventually create Hashemite-ruled kingdoms in Jordan and in Iraq, as well as Hejaz. The changing boundaries of the Ottoman Hejaz Vilayet contributed to uncertainties between the neighbouring Hashemite kingdoms, particularly the competing claim with Transjordan over the inclusion of the sanjak of Ma'an, including the cities of Ma'an and Aqaba. Hussein refused to ratify the 1919 Treaty of Versailles, and in response to a 1921 British proposal to sign a treaty accepting the Mandate system stated that he could not be expected to "affix his name to a document assigning Palestine to the Zionists and Syria to foreigners." A further British attempt to reach a treaty failed in 1923–24, and negotiations were suspended in March 1924; within six months the British withdrew their support in favor of their central Arabian ally Ibn Saud, who proceeded to conquer Hussein's kingdom. The League of Nations Covenant provided for membership to the signatories of the Peace Treaties; the Hejaz was one of three that failed to ratify Versailles.
