Seven Pillars of Wisdom by T.E. Lawrence

The position of the Sherif of Mecca had long been anomalous. The title of 'Sherif implied descent from the prophet Mohammed through his daughter Fatima, and Hassan, her elder son. Authentic Sherifs were inscribed on the family tree--an immense roll preserved at Mecca, in custody of the Emir of Mecca, the elected Sherif of Sherifs, supposed to be the senior and noblest of all. The prophet's family had held temporal rule in Mecca for the last nine hundred years, and counted some two thousand persons.

The old Ottoman Governments regarded this clan of manticratic peers with a mixture of reverence and distrust. Since they were too strong to be destroyed, the Sultan salved his dignity by solemnly confirming their Emir in place. This empty approval acquired dignity by lapse of time, until the new holder began to feel that it added a final seal to his election. At last the Turks found that they needed the Hejaz under their unquestioned sway as part of the stage furniture for their new pan-Islamic notion. The fortuitous opening of the Suez Canal enabled them to garrison the Holy Cities. They projected the Hejaz Railway, and increased Turkish influence among the tribes by money, intrigue, and armed expeditions.