the institution of the Caliphate had disappeared in the political degeneration of Islâm. However, they did not imagine him as a pope, but as a supreme ruler; above all as the amîr-al-muʾ-minîn, commander of the legions of Islâm, which sometime would make the whole world bend to its power.
The Caliph, the lieutenant of Allah's Messenger, and the jzhâd, the holy war against the whole world outside Islâm: with those two names was indissolubly connected the remembrance of those two brilliant centuries in which the course of circumstances seemed to justify the Mohammedan ambition for world-dominion. Whatever disappeared in reality survived in legend; the worship of the shadow-Caliphs of Bagdad made it easier for many Mohammedans to forget the failure of their political ideal.
When Bagdad had fallen and a large
