A proof of the religious infatuation, or the blind confidence in destiny, which hurried the Moslem commanders of those days into the most extravagant enterprises, is furnished in the invasion of the once proud empire of the Pharaohs, the mighty, the mysterious Egypt, with an army of merely five thousand men. The caliph Omar himself, though he had suggested this expedition, seems to have been conscious of its rashness, or rather to have been chilled by the doubts of his prime counsellor Othman; for, while Amru was on the march, he despatched missives after him to the following effect: "If this epistle reach thee before thou hast crossed the boundary of Egypt, come instantly back; but if it find thee within the Egyptian territory, march on with the blessing of Allah, and be assured I will send thee all necessary aid." The bearer of the letter overtook Amru while yet within the bounds of Syria; that wary general either had secret information or made a shrewd surmise as to the purport of his errand, and continued his march across the border without admitting him to an audience. Having encamped at the Egyptian village of Arish, he received the courier with all due respect, and read the letter aloud in the presence of his officers. When he had finished, he demanded of those about him whether they were in Syria or Egypt. "In Egypt," was the reply. "Then," said Amru, "we will proceed, with the blessing of Allah, and fulfil the commands of the Caliph." The first place to which he laid siege was Farwak, or Pelusium, situated on the shores of the Mediterranean, on the isthmus which separates that sea from the Arabian Gulf, and connects Egypt with Syria and Arabia. It was therefore considered the key to Egypt. A month's siege put Amru in possession of the place; he then examined the surrounding country with more forethought than was generally manifested by the Moslem conquerors, and projected a canal across the isthmus, to connect the waters of the Red Sea and the Mediterranean. His plan, however, was condemned by the Caliph as calculated to throw open Arabia to a maritime invasion of the Christians. Amru now proceeded to Misrah, the Memphis of the ancients, and residence of the early Egyptian kings. This city was at that time the strongest fortress in Egypt, except Alexandria, and still retained much of its ancient magnificence. It stood on the western bank of the Nile, above the Delta, and a little east of the pyramids. The citadel was of great strength and well garrisoned, and had recently been surrounded with a deep ditch, into which nails and spikes had been thrown, to impede assailants.