CALIPH and CALIPHATE. - The Arabic title halifah means “successor,” “lieutenant,” and appears frequently in the Qur'an as well, but never in the technical sense which it later acquired, that of lieutenant of the prophet (halifat rasūl Allāh). This title appears to have been assumed for the first time by the caliph 'Omar, and thenceforth “caliph” meant the head of the Muslim theocratic state; it is therefore in no way parallel to the Catholic title of “pope,” and it would be erroneous to regard the caliph as the “pope of the Muslims.”
After the death of the prophet (632), leadership of the Muslim community passed to Abū Bakr (632-34), then to 'Omar (634-44), 'Otmān (644-56), and 'Alī (656-61). These are the four so-called “orthodox” caliphs (ra'īddin). From the politico-religious struggles following the assassination of the caliph 'Otmān and the caliphate of 'Alī arose the Šī'ah, which divided, and still divides, the Muslim world: the Shiites recognize 'Alī and his descendants as the only legitimate caliphs or imām.
This hereditary principle, contrary to the pure Arab-Bedouin traditions, nevertheless also gained ground among non-Shiites, and the four “orthodox” caliphs were followed by the dynasty of the Ommiadi (661-750), bitter enemies of the partisans of 'Alī. Yet so strong was the Arab “democratic” tradition that the caliph who came to power had to receive a formal ba'ah (official recognition) from the Muslim communities. Under the Ommiadi, the capital of the Arab-Muslim empire was transferred from Medina to Damasco: the Ommiadi emphasized especially the political aspect of their functions.
The Ommiade dynasty was followed by that of the 'abbāsidi (750-1258), which transferred the capital to Bagdad. With the accession to power of the 'Abbāsidi (who obtained the throne also with the aid of the Shiites, whom they subsequently began to persecute), Persian monarchical traditions prevailed over the democratic simplicity of the Bedouins characteristic of the “orthodox” caliphs and the first Ommiadi, when the caliph was still a primus inter pares. At the same time, the 'abbāsidi caliphs gave greater importance to the religious aspect of their office, clothed themselves in the mantle of the Prophet, and flaunted ties of kinship with the family of Maometto. During the reign of the 'Abbāsidi, various more or less independent Muslim princes came into being, and by about 946 no effective political power remained in the hands of the caliph of Bagdad, although he was still regarded by theorists, mindful of ancient greatness, as the source of all authority in the Muslim world. Rival caliphates to that of Bagdad were, however, formed, the most important of which were the Ommiade caliphate of Spain (the title of caliph was assumed by 'Abdarrahmān III in 928) and the Shiite caliphate of the Fātimidi of Egypt (909-1171). When Hūlāgū, grandson of Gengiskan, occupied and devastated Bagdad, killing the last 'abbāsidi caliph Musta'ṣim (1258), the Muslim world for the first time lacked a head.
The descendants of the 'abbāsidi caliphs who held the office of caliph for many years thereafter in Cairo (1261-1517) were merely puppets in the hands of the Mamluk sultans of Egypt and possessed no power, being ignored by the greater part of the Muslims. When the Ottoman sultan Selim made his triumphant entry into Cairo (1517) and brought Mutawakkil, the last shadow of an 'abbāside caliph, to Costantinopoli, he had already assumed the title of caliph on his own account, a title later sought to be legitimized (according to Sunni doctrine the caliph must belong to the family of the Coreisciti) by the legend of an alleged investiture of Selim by Mutawakkil.
From then on the powers of the caliphate were held by the Ottoman sultans until 1922, when, the sultanate having been abolished, the caliphate was artificially maintained as a merely religious office, itself abolished in 1924.
As has been said above, in no respect can the caliph be compared, as regards his functions, to a “pope.” The office of the caliph consists solely in holding together and governing politically that religious community which alone has the right to decide (through its learned men, 'ulemā', muftis, etc.) religious questions not already settled by the Qur'an and the sunnah (v.). The caliph is a believer like any other and has no legislative power in religious matters. If, moreover, it is borne in mind that according to orthodox theory the caliphate must belong, as has been said, to the family of the Coreisciti, it may be concluded that the caliphate in its legitimate form in fact ceased to exist in 1258, with the fall of Bagdad, and that the Muslim world has for several centuries been unaccustomed to being governed by a caliph.
As for the Shiite idea of the caliph, it should be noted that the concept of the imām (v.) is fundamental in the B'ah. The caliph or imām possesses superhuman qualities, and the imamate is restricted not only to the tribe of the Coreisciti but to the family of 'Alī: the Shiites, indeed, with few exceptions, reject the concept of the electivity of the caliph and affirm that the superhuman qualities of 'Alī are hereditary in all his successors.
According to the ultra-democratic conceptions of the ḥāriǧiti (v.), on the other hand, the caliphate is not indispensable (the functions of the caliph may be exercised by the community), and any believer may be elected caliph.