the line of the E. E. F.'s advance, a line guaranteed to all Islam by its Ottoman Caliph and additionally guaranteed to Islam in India by the Government of India's undertaking that the Caliphate was a matter for Moslem opinion alone to decide. This guaranteed line, however, lay across the Cairo-Calcutta leg of the Cape-to-Cairo-to-Calcutta triangle and in due time the Foreign Office handed down its instructions. The Residency in Cairo began the extemporization of a British Arabia which should pivot on Mecca with provincial capitals at Damascus and Bagdad.
Thus was carried into effect one of the most momentous decisions in the history of an Empire which once called itself "the greatest Moslem Power in the world," a decision which plumbs the depths of the British surrender in the Anglo-Russian Treaty of 1907. The Ottoman Caliphate was the last great barrier in front of imperialism. The 1907 Treaty broke it.
The Residency now lost no time in establishing contact with the Grand Sherif of Mecca. The Ottoman Caliph hurried reinforcements to the Hejaz, but the Sherif's son Feisal drew a cordon around them in Medina at the southern terminus of the Hejaz Railway. Although British officers directed him in repeated efforts to isolate Medina by cutting the Hejaz Railway, the Caliph succeeded in holding it until after the Ottoman Government signed its armistice in 1918, but throughout the rest of the Hejaz, his garrisons sooner or later were removed to British prison camps in Egypt. In the summer of 1917 the Grand Sherif declared his independence of Constantinople, assuming the title of King Hussein I.
