Representing the British government, Sir Henry McMahon (1862-1949), British High Commissioner in Cairo negotiates in 1915-16 with Husayn Ibn Ali, the Sherif of Mecca. Sherif Husayn believes that his Hashemite family should lead the Arabs during and after WWI. The British government promises to support Husayn if he supports the British war effort to defeat Turkey during this period. There is, however, never a concrete understanding on the geographic borders of an Arab state that the Hashemites would head—and the area of Palestine is not mentioned by name in the exchange. Parallel to the Husayn-McMahon Correspondences, the British were negotiating with other allies in the war, as well as the Zionists about varying degrees of influence that each might have in these Ottoman Arab lands, including Palestine. In 1921, Husyan’s son Abdullah becomes Emir of Transjordan, securing Hashemite-family control of that area until today. The British give the Zionists an opportunity to establish a national home in Palestine, which in turn caused great anger amongst Arab nationalists. (source)