About this time the veteran Emir, Abu-al-Aghlab, died, full of years and glory. The populace of Palermo, elated by success, and desirous to assert, upon every occasion, their independent and seditious spirit, without notice to the court of Kairoan, chose by acclamation, as governor of the colony, Abbas-Ibn-Fadl, a captain noted for the determination of his character and the ferocity of his manners. Under his administration the war was prosecuted more vigorously than ever. The fields of the industrious peasant, however remote, were never secure from the destructive visits of the Arab freebooter. Such Christian settlements as were sufficiently wealthy were permitted to retain their lands upon payment of a tribute usually largely in excess of that prescribed by Mohammedan law, and which was but a doubtful guaranty of safety when the caprice of the conqueror suggested an increase of his already rapacious and extravagant demands. The requirements of a population constantly engaged in warfare necessitated the employment of a large number of slaves in the cultivation of the soil. These were obtained not only from captives taken in battle, but as a portion of the tribute wrung from the cowardly Greeks, who did not hesitate to sacrifice their retainers, and even their kinsmen, for the enjoyment of a temporary security. The Moors, conscious of the helplessness of their infidel tributaries, whom they considered as already vanquished and indebted for even existence to their own moderation, often refused offerings of gold and precious commodities, and exacted instead the delivery of a prescribed number of human cattle, whose lives were speedily extinguished by the severe labor to which they were subjected in the pestilential atmosphere of the coast and of the marshy valleys of the interior, where the culture of rice was conducted with great profit and with a flagrant disregard of the mortality it occasioned.