sentences:  It is clearly possible that the Persian forces did spend some prolonged time in training, since it took four years for them to respond to the Egyptian victory at Pampremis.Although neither author gives many details, it is clear that when Megabyzus finally arrived in Egypt, he was able to quickly lift the Siege of Memphis, defeating the Egyptians in battle, and driving the Athenians from Memphis.The Athenians now fell back to the island of Prosopitis in the Nile delta, where their ships were moored.