The Hashemite Kingdoms. The Hashemites - the Prophet Muhammad's clan, sharifs of Mecca for a thousand years - briefly ruled four kingdoms in the 20th century. When Sharif Hussein launched the Arab Revolt against the Ottomans (1916) in alliance with Britain, he proclaimed himself King of the Arabs, ruling the Hejaz; his sons became the dynasts of the post-Ottoman settlement: Faisal, king of Syria for four months in 1920, expelled by France and crowned king of Iraq (1921); Abdullah, given the new emirate of Transjordan east of the river (1921).
The fortunes of the four thrones diverged. Hussein, refusing to abandon his claim to the caliphate and his quarrel with Ibn Saud, lost the Hejaz itself: Saudi forces took Mecca in 1924 and Jeddah in 1925, ending a millennium of Hashemite rule in the holy cities. Faisal's Iraq prospered as a kingdom after 1932 but was convulsed by coups and the 1941 war; his grandson Faisal II and the whole Iraqi royal house were massacred in the revolution of 14 July 1958, ending the Iraqi branch.
Abdullah's Transjordan proved the survivor. Granted independence in 1946 as the Hashemite Kingdom of Transjordan, it seized the West Bank and East Jerusalem in the 1948 war and renamed itself Jordan; Abdullah was assassinated by a Palestinian gunman at Jerusalem's al-Aqsa Mosque (1951), and after the troubled reign of his son Talal, his grandson Hussein - eighteen at accession, 1952 - ruled for 46 years through wars and upheavals.
The Hashemite kingdoms' century left a double legacy: the Arab Revolt's dream of Arab unity, betrayed (in Arab memory) at Sykes-Picot, and one enduring state - Jordan, where Hussein's son Abdullah II reigns today as the last Hashemite king, custodian of Jerusalem's holy places and heir of the sharifs of Mecca.