STILL throughout the whole period of the decline of the Caliphate up to the date of the death of Musta'f}im (1258), the Caliph was to all orthodox Sunnis the Commander of the Faithful, and as Successor of the Prophet he was held to be the source of all authority and the fountain of honour. The Caliph by his very name led men's thoughts back to the founder of their faith, the promulgator of their system of sacred law, and represented to them the principle of established law and authority. Whatever shape the course of external events might take, the faith of the SunnI theologians and legists in the doctrines expounded in their textbooks remained unshaken, and even though the Caliph could not give an order outside his own palace, they still went on teaching the faithful that he was the supreme head of the whole body of Muslims. Accordingly, a diploma of investiture sent by the Caliph, or a title of honour conferred by him, would satisfy the demands of the religious law and tranquillize the tender consciences of the subjects of an independent prince, though the ruler himself m~ght remain entirely autonomous and be under no obligation of obedience to the puppet Caliph.