Mohammed Ibn Abdullah, a lamplighter in the mosque at Cordova, had made his way to remote Bagdad to study at the feet of Abu Hamid Algazali, a celebrated doctor of Moslem law. The strange adventures, so characteristic of his age and nation, by which the lowly student became a religious reformer--a Mahdi--and a conqueror in Africa, and at length overthrew the Almoravides, both to the north and the south of the Straits of Gibraltar, forms a most curious chapter in the history of Islam; but in a brief sketch of the fortunes of medieval Spain, it must suffice to say that having established his religious and military power among the Berber tribes of Africa, Ibn Abdullah, the Mahdi, landed at Algeciras in 1145, and possessed himself in less than four years of Malaga, Seville, Granada, and Cordova. The empire of the Almoravides was completely destroyed; and, before the close of the year 1149, all Moslem Spain acknowledged the supremacy of the Almohades. These more sturdy fanatics were still African rather than Spanish sovereigns. Moslem Spain was administered by a Vali deputed from Morocco; and Cordova, shorn of much of its former splendor, was the occasional abode of a royal visitor from Barbary. For seventy years the Almohades retained their position in Spain. But their rule was not of glory but of decay. One high feat of arms indeed shed a dying luster on the name of the Berber prince who reigned for fifteen years (1184-99) under the auspicious title of Almanzor, and his great Moslem victory over Alfonso II. at Alarcon in 1195 revived for the time the drooping fortunes of the Almohades. But their empire was already doomed, decaying, disintegrated, wasting away. And at length the terrible defeat of the Moslem forces by the united armies of the three Christian kings at the Navas do Tolosa in 1212, at once the most crushing and the most authentic of all the Christian victories of medieval Spain, gave a final and deadly blow to the Moslem dominion of the Peninsula. Within a few years of that celebrated battle, Granada alone was subject to the rule of Islam. It was in the year 1228 that a descendant of the old Moorish kings of Saragossa rebelled against the Almohades and succeeded in making himself master not merely of Granada, but of Cordova, Seville, Algeciras, and even of Ceuta, and, obtaining a confirmation of his rights from Bagdad, assumed the title of Amir ul Moslemin--Commander of the Moslems--and Al Mutawakal--the Protected of God.