Alexandria was tranquil under the government of its conqueror, but after the death of Omar, Amrou was recalled. The Greek emperors feeling keenly the loss of Egypt, took advantage of this circumstance to make a descent upon its coasts. At the sight of their ancient compatriots, the Alexandrians rose, took up arms, drove out the infidels, and opened their gates to the Greeks. Amrou, being informed of this revolt, returned from Libya, chastised Alexandria, and drove the Christians from its walls. Persuaded that such an example would be sufficient to restrain the Egyptians, he again set out for Tripoli; but the Greeks returned once more, and took possession of the port and the city of Alexandria. Amrou, exceedingly irritated, came back; but he had sworn, this time, to dismantle this indocile city. He kept his word; he protected the Alexandrians as much as he could from the fury of the soldiery; but he razed the walls, diminished its extent, and left the inhabitants to exist amidst the ruins of their country. SIXTH SIEGE, A.D. 1171. Egypt belonged for three centuries to the Fatimite caliphs; but this race degenerated: divided among themselves for the possession of power, one of its two branches had the imprudence to call in the sultan of Damascus to its aid. After several battles, the latter was the conqueror, but he kept his conquest for himself. Saladin, his son, became, in 1171, sultan of Egypt. The descendants of this great man were, in their turn, displaced by the Mamelukes and their beys, a singular kind of militia, continually recruited by slaves from Mount Caucasus; themselves choosing their sultans, as the prætorian guards had done, and, like them, disposing of power. Egypt was conquered by the Ottomans. Selim I. contented himself with weakening, for the time, the influence of the Mamelukes; but, always ambitious, they resumed, by degrees, their authority under his weak successors, and only left the Ottoman Porte a shadow of power in the provinces over which they tyrannized. SEVENTH SIEGE, A.D. 1799.