At Gordium, where Alexander's troops spent their first winter in Asia, there stood on the citadel the cart in which, according to the story, Midas, a peasant's son, had driven to the meeting-place of the Phrygians on the day when unexpectedly he was proclaimed their king. The legend had spread thence around the country that whosoever unfastened the knot of cornel bark which held the yoke to the shaft of this cart would become king of Asia. This task Alexander essayed in vain. Then he drew his sword and cut the thong in two. Thereby he announced both his departure from the policy of Philip, which had been simply to emancipate the Ionian Greeks, and the forthcoming execution of his own policy, which was to take from the Persians their dominion over Asia. After his first victory at the Granicus River Alexander advanced along the Ægean seaboard as far as Cilicia, securing as he went all the coast towns in Asia Minor which had contributed ships to the Persian fleet. This plan of campaign he adhered to after his second victory at Issus over Darius, when, instead of keeping in touch with his defeated enemy and of following him into the interior, as the ordinary common sense of war commanded, he let the King go, and spent a year in seizing the naval towns between Cilicia and Cyrene. This he did in order to destroy the Persian fleet, an end which he could not otherwise attain, since he had no ships of his own. To leave the enemy's fleet in possession of the Mediterranean, however, while he was campaigning far in the heart of the continent would have been to jeopardize all that he had already accomplished, and, in particular, to leave to the Persians the means of causing a general insurrection among the Greeks, whom he rightly feared more than the Persians. This long détour southward to Egypt is, accordingly, amply explained by sound strategical considerations. That, however, cannot be said of Alexander's sensational march through the Sahara to the oasis of Siwah in the hinterland of Cyrene. There, in mysterious aloofness, lay an oracle of the Egyptian Ammon whom the Greeks called Zeus. Just as Dodona in Epirus had been eclipsed in times past as an oracular seat by the shrine of Apollo at Delphi, so this in turn had waned in prestige and credit when it became known gradually to the Greeks that Zeus Ammon revealed unfailingly the future to his priests at Siwah. For more than two generations prior to Alexander's visit the Ammonium had been the Mecca of pilgrims, and the recipient of gifts from all parts of the Greek world. Athens had even built a sacred trireme, the so-called "ship of Ammon," to carry public messengers to and from the oracle. In Egypt the Ammon of Siwah was of no account as compared with the Ammon of Thebes; but among the Greeks the Ammon that was known and revered was, to speak with Plato, the Ammon of Cyrene. Alexander knew well the impression which would be produced in the