The invasion and sack of Medina by the Syrians, bent upon retribution for the murder of Othman, had caused a great emigration from Arabia, and thousands of the descendants of the proudest families of the Holy Cities had established themselves in Africa, and had rendered great aid to the projects of Musa. Their incorporation into the armies of Al-Maghreb and Iberia sensibly affected the fortunes of the latter country, and indirectly led to the restoration of the dynasty of the Ommeyades. Four sons of Musa had accompanied him in his campaign, and now deputing his authority to the two eldest, he despatched them to the South and West, where a few remaining Berber tribes still asserted their independence. Following the example of their father they exterminated such tribes as dared to resist, and in a few months returned to Kairoan, whither Musa had retired with considerable spoil and a large number of captives. In the mean time, the latter, recognizing the supreme importance of naval operations, and treating with contempt the absurd prejudice of his countrymen whose superstitious dread of the sea amounted at times to absolute terror, ordered the refitting of the dock-yards and harbors of Carthage, whose substantial quays had been little impaired by the successive calamities which had befallen the city. A hundred vessels were built, launched, and manned; Abdallah was appointed admiral; the fleet cruised along the coast of the Mediterranean, and crossing to Sicily, sacked the city of Linosa and returned in triumph with a booty of twenty thousand pieces of gold. Four years afterwards a descent was made by Abdallah on the Balearic Isles, and Majorca was, after a short campaign, added to the dominions of the Khalif. Their incorrigible duplicity and restlessness, and the absence of a competent military force, again impelled the tribes of the interior to revolt. Taking the field at the head of a picked force, Musa, with trifling difficulty, took Tangier, the last fortified post held by the Greeks in Al-Maghreb; and sending his son Merwan with five thousand cavalry against Sus-al-Aska, the head-quarters of the insurgents, soon had the satisfaction of learning that the rebellion was subdued, and the recalcitrant Berbers punished with a rigor unexampled even in the sanguinary wars of Africa. After making two attempts to capture Ceuta, one of the keys of the strait separating Africa from Europe, both of which the gallant behavior of the governor, Count Julian, rendered ineffectual, Musa appointed Tarik-Ibn-Zeyad, a Berber convert, formerly his slave, and now one of his most trusty officers, to the command of Tangier, and returned to Kairoan.