In the year 868 Ahmed ibn Túlún, the son of a Turkish slave, who had been appointed viceroy of Egypt by the Caliph el M‘otazz Billah, rebelled against his master’s authority, and assumed the style and title of Sultán, or independent sovereign. The kingdom remained in his family about thirty years, when it was retaken by Mohammed ibn Suleimán, general of the Caliph el Moktadhí Billah, and the authority of the Abbassides was again established in Egypt. This state of things, however, continued but for a short time, and in 936 the government of Egypt was again usurped by a Turk named Ikhshíd, who, after some opposition from the troops of the Er Rádhí Billah (the last of the caliphs who enjoyed the authority or deserved the name), obtained undisputed possession of Syria. He was nominally succeeded by his sons, but the government remained in the hands of his black slave, Káfúr, who ultimately contrived to seat himself upon the throne. At his death the kingdom passed to ‘Alí el Ikshíd, a nephew of the founder of the family; but, after a short reign of one year, he was deposed (A.D. 970) by Jauher, the general of El Mo‘ezz li dín Allah, fourth of the Fatemite caliphs. This dynasty (the Fatemite, or Ismáïlí) was the most formidable of all who had resisted the authority of the caliphs of Baghdád; for it was not as the insurgent possessors of a province that they asserted their independence, but, as legitimate heirs, they disputed their master’s title to the caliphate itself. The family traced its origin to Mohammed, through Fatimah, wife of ‘Alí ibn Abi Táleb, and daughter of the prophet; and on the strength of this illustrious pedigree, they claimed to be the true successors of the prophet, and rightful heirs to the supreme authority. Their pretensions were combated with great obstinacy by the Abbasside princes, but there seems good reason for believing that their claims were well-grounded. The founder of the house was one ‘Obeid Allah, who, at the head of a number of political and religious fanatics, had succeeded in establishing himself in Irák and Yemen. After a series of romantic adventures, he made himself master of Africa (A.D. 910), where he assumed the title and authority of Caliph, and gave himself out to be the Mehdí, or last of the Imáms, foretold by Mohammed. At his death, which happened in A.D. 934, he was succeeded by his son, Al Cáïm bi Amr Illah, who reigned until A.D. 946. His son, El Mansúr Ismael, then came to the throne, and dying in 952, the caliphate passed into the hands of El Mo‘ezz li dín Allah Abu Temím Ma’ad. It was this prince who conquered Egypt and founded the city of Cairo, which then became the seat of empire. He died in 969, and was succeeded by his son El ‘Azíz billah Abu Mansúr Nizár. His death happened in October, A.D. 996; and the caliphate then passed to El Hakem bi Amr Illah, about whom it will be necessary to speak more in detail.