=The Rise of the House of Abbâs.=—In the middle of the eighth century of the Christian era Western Asia was the scene of a great revolution, which resulted in the downfall of the Ommeyades. The revolt was headed by a descendant of Abbâs, an uncle of the Prophet. The contest between the Ommeyades and Abbassides reminds us, in its bitterness and cruelty, of the later quarrel between the White and the Red Rose of England. =Foundation of the Ommeyade Caliphate in Spain, 756 A.C.=—The Abbassides were successful and the Ommeyades were practically annihilated. Only one solitary scion of this ill-fated family escaped to Spain, where he founded the brilliant empire of Cordova. The Abbassides held the Eastern Caliphate with its seat in Bagdad from 756 A.C. to 1258 A.C. =Destruction of Bagdad.=—When Bagdad was destroyed by the Mongols, a member of the Abbasside family succeeded in escaping to Cairo. Here he was recognised as Caliph by the Sultan of Egypt, and was surrounded by all the dignity attached to the pontifical office. The eighth Pontiff, by a formal act, renounced the Caliphate in favour of Sultan Selim, the great Ottoman conqueror. =The Title of the Ottoman Caliphs.=—The title of the Sultans of Turkey to the spiritual headship of Islâm is based on this renunciation, and on the possession by them of the seal, mantle, and staff of the Prophet; and their claim is recognised as valid by the whole of the Sunni world. =Mansûr, the second Abbasside Caliph.=—The first eight Caliphs of the house of Abbâs were men of great ability and force of character. Mansûr, the second sovereign, was the real founder of the Abbasside polity and system of administration, which became in after years the model for all civilised Mussulman States, and which were copied in later times by the Christian countries of Europe. =Hârûn-ar-Rashîd and Mâmûn.=—Under Hârûn-ar-Rashîd, the hero of the _Arabian Nights_, and his son Mâmûn the Caliphate of Bagdad attained its zenith. It was indeed the Augustan age of the Arabs. But the achievements of the Moslems in the domain of intellect extend over the whole period during which the Abbassides exercised their suzerainty over Western Asia and Egypt. =The Ommeyade Caliphate of Spain.=—The Empire founded in Spain by the Ommeyade Abdur Rahmân, surnamed _Dâkhil_ (the ‘Enterer’), rivalled that of Bagdad in the glory of arms and learning. The eighth sovereign of this dynasty, Abdur Rahmân (an-Nâsir), who assumed the title and dignity of Caliph, was the most gifted monarch who has ever ruled over Spain. With the disintegration of the Cordovan Caliphate, in the eleventh century of the Christian era, the country split up into several small kingdoms, until they were re-united under the ægis of the Almoravide monarchs of North Africa.[44] =The Fatimide Caliphate of North Africa.=—In the beginning of the tenth century, a descendant of Ali, Obaidullah, surnamed _al-Mahdi_ (the ‘Guide’), founded the great Fatimide Empire of Northern Africa.