1911 Encyclopædia Britannica/Caliph
CALIPH, Calif, or Khalif (Arab, khălīfa; the lengthening of the a is strictly incorrect), literally “successor,” “representative,” a title borne originally by Abu Bekr, who, on the death of Mahomet, became the civil and religious head of the Mahommedan state. In the same sense the term is used in the Koran of both Adam and David as the vicegerents of God. Abu Bekr and his three (or four) immediate successors are known as the “perfect” caliphs; after them the title was borne by the thirteen Omayyad caliphs of Damascus, and subsequently by the thirty-seven Abbasid caliphs of Bagdad whose dynasty fell before the Turks in 1258. By some rigid Moslems these rulers were regarded as only amirs, not caliphs. There were titular caliphs of Abbasid descent in Egypt from that date till 1517 when the last caliph was captured by Selim I. On the fall of the Omayyad dynasty at Damascus, the title was assumed by the Spanish branch of the family who ruled in Spain at Cordova (755-1031), and the Fatimite rulers of Egypt, who pretended to descent from Ali, and Fatima, Mahomet’s daughter, also assumed the name (see Fatimites).
According to the Shi‘ite Moslems, who call the office the “imamate” or leadership, no caliph is legitimate unless he is a lineal descendant of the Prophet. The Sunnites insist that the office belongs to the tribe of Koreish (Quraish) to which Mahomet himself belonged, but this condition would vitiate the claim of the Turkish sultans, who have held the office since its transference by the last caliph to Selim I. According to a tradition falsely ascribed to Mahomet, there can be but one caliph at a time; should a second be set up, he must be killed, for he “is a rebel.” (See Mahommedan Institutions.)