The recorded history of the Moorish Empire does not really commence, however, until half a century later, when an Arab missionary, Mulai Idris ben Abdallah, a direct descendant of the Prophet, a fugitive who had fled from Arabia during the bloody struggles between the rival claimants to the caliphate, settled in northern Morocco and founded a city on a hill within sight of the Roman ruins of Volubilis. Islam had already been established in these parts for eighty years, and so Idris, by virtue of the sanctity attaching to him as a relative of the Prophet, experienced no great difficulty in uniting the Berbers of the region into a confederation which was greatly extended by his son, Idris II, the builder of Fez, which became the capital of the Idrisi kingdom. Meanwhile there was being founded in southern Morocco what later grew to be the kingdom of Marrákesh. Toward the close of the thirteenth century the kingdoms of Fez and Marrákesh became united under one ruler, whose successor, after numerous dynastic changes, Arab and Berber, is the present sultan of Morocco. The sixteen rulers of the Idrisi line, an Arab dynasty, controlled northern Morocco for nearly two hundred years, though they were in part supplanted by the Berber family of Miknasa in 922 and ousted altogether by another Berber dynasty, the Maghrawa, in 988. These last were exterminated in turn by a third Berber dynasty, the Murabti (or Almoravides, as they are better known), who added the remainder of Morocco, most of Spain and Portugal, and the sultanate of Tlemcen to their dominions. Their principal existing monument is the city of Marrákesh. In 1149 the Almoravide power was overthrown by the Muwahhadi (Almohades), another Berber horde. Under them the Moorish Empire reached its zenith at the close of the twelfth century, when it included, in addition to Morocco and the Iberian peninsula, what are now Algeria, Tunisia, and Tripolitania, its borders extending to the frontiers of Egypt, which the Moors were prevented from occupying only by the rise of Saladin. To them we owe the Alcázar, the Giralda, and the Torre del Oro in Seville, the Hasan tower at Rabat, the Kutubiya tower at Marrákesh, the castle of Gibraltar, and a portion at least of the Alhambra at Granada. Yet before the thirteenth century had reached the half-way mark the Almohades had been driven out of Spain and had lost all of their vast empire save what is now known as Morocco, whence they were finally ousted by the Marinides—a Spanish corruption of Beni Marin. The Marinides, Berbers like their predecessors, ruled in Morocco for something over three hundred years, yet they have scarcely left a mark upon the country. They were succeeded by the short-lived dynasty of the Wattasi, the chief episode of their reign being the expulsion of the Moors from Spain by the Catholic princes, Boabdil, the last king of Granada, and his followers taking refuge in Morocco, where they built themselves the city of Tetuan.