No further defection took place during the reign of Xerxes; but in B.C. 460, after the throne had been occupied for about five years by Xerxes' son, Artaxerxes, a second rebellion broke out, which led to a long and terrible struggle. A certain Inarus, who bore rule over some of the African tribes on the western border of Egypt, and who may have been a descendant of the Psamatiks, headed the insurrection, and in conjunction with an Egyptian, named Amyrtæus, suddenly attacked the Persian garrison stationed in Egypt, the ordinary strength of which was 120,000 men. A great battle was fought at Papremis, in the Delta, wherein the Persians were completely defeated, and their leader, Achæmenes, perished by the hand of Inarus himself. Memphis, however, the capital, still resisted, and the struggle thus remained doubtful. Inarus and Amyrtæus implored the assistance of Athens, which had the most powerful navy of the time, and could lend most important aid by taking possession of the river. Athens, which was under the influence of the farsighted Pericles, cheerfully responded to the call, and sent two hundred triremes, manned by at least forty thousand men, to assist the rebels, and to do as much injury as possible to the Persians. On sailing up the Nile, the Athenian fleet found a Persian squadron already moored in the Nile waters, but it swept this obstacle from its path without any difficulty. Memphis was then blockaded both by land and water; the city was taken, and only the citadel. Leucon-Teichos, or "the White Fortress," held out. A formal siege of the citadel was commenced, and the allies lay before it for months, but without result. Meanwhile, Artaxerxes was not idle. Having collected an army of 300,000 men, he gave the command of it to Megabyzus, one of his best generals, and sent him to Egypt against the rebels. Megabyzus marched upon Memphis, defeated the Egyptians and their allies in a great battle under the walls of the town, relieved the Persian garrison which held the citadel, and recovered possession of the place. The Athenians retreated to the tract called Prosopitis, a sort of island in the Delta, surrounded by two of the branch streams of the Nile, which they held with their ships. Here Megabyzus besieged them without success for eighteen months; but at last he bethought himself of a stratagem like that whereby Cyrus is said to have captured Babylon, and adapted it to his purpose. Having blocked the course of one of the branch streams, and diverted its waters into a new channel, he laid bare the river-bed, captured the triremes that were stuck fast in the soft ooze, marched his men into the island, and overwhelmed the unhappy Greeks by sheer force of numbers. A few only escaped, and made their way to Cyrene. The entire fleet of two hundred vessels fell into the hands of the conqueror; and fifty others, sent as a reinforcement, having soon afterwards entered the river, were attacked unawares and defeated, with