The Prophet left no direct heirs, and this led to continual wrangling among the various tribes; even the succession of Abu–bekr, father of Mohammed’s favourite wife Ayeshah, did not settle anything, for at his death the question was reopened. Not right, but might, however, prevailed with the Arabs, and about the year 661 the first calif of the Ommiades seated himself at Damascus. One of this line was in power when Spain was invaded, but about the middle of the eighth century three brothers came forward to dispute his rights. The calif was killed, and eighty Ommiades of influence, invited to a feast at Damascus, were murdered in cold blood. Thus arose the line of Abbassides, so called from alleged descent from Abbas, uncle of Mohammed. Like most of the Arab rulers, the Abbassides signalled their rise to power by deeds of blood, their first effort being toward the entire obliteration of the house of Ommiades. But two of this noble house escaped: one fled to Arabia, where his descendants ruled a while; and the other to Africa, where, among the devoted adherents of his line, the Bedouins and the Berbers, he passed several years under their protection. It happened that most of the Moslem chiefs in Spain were also allied to the house of Ommiades, and when they learned that the young Syrian Abderrahman was wandering in Africa a fugitive, with a price upon his head, they earnestly entreated him to come over and become their ruler. Yusef, the last emir of the Abbassides, was routed in battle and sent away, and Spain at last made independent of Eastern influence under a king of her own—the first of a line which governed, in the main wisely, for nearly three hundred years. Prince Abderrahman made the city of Cordova the seat of the Western califate, and under him it became a centre of learning as well as prosperity, rivalling all other cities of the peninsula. Magnificent palaces were built, hospitals and mosques, one of the last named being the glorious mosque of Cordova, its site four acres in extent, renowned throughout the world for its beauty. This was begun by Abderrahman in the year 786, and has lasted to our time, with its unrivalled mosaics, tiles, and arabesques, and its thousand columns of porphyry and alabaster. Then were begun those vast irrigation works which reclaimed the desert plains of the country and made them flourish with vegetation; the immense aqueducts, the bridges, towers, and walls of defence. And yet the reign of Abderrahman was by no means a peaceful one, as he had to placate the many different sects and tribes of his own countrymen on the one hand, and the Jews and Christians on the other. In the north was a turbulent Christian population, ever at war; in the south, a Mohammedan population always quarrelling over the division of spoils, and particularly of the conquered territory.