There remained one who was destined to be the greatest warrior of all. This was Achilles, the son of Thetis,--foretold in the day of Prometheus as a man who should far outstrip his own father in glory and greatness. Years had passed since the marriage of Thetis to King Peleus, and their son Achilles was now grown to manhood, a wonder of strength indeed, and, moreover, invulnerable. For his mother, forewarned of his death in the Trojan War, had dipped him in the sacred river Styx when he was a baby, so that he could take no hurt from any weapon. From head to foot she had plunged him in, only forgetting the little heel that she held him by, and this alone could be wounded by any chance. But even with such precautions Thetis was not content. Fearful at the rumors of war to be, she had her son brought up, in woman's dress, among the daughters of King Lycomedes of Scyros, that he might escape the notice of men and cheat his destiny. To this very palace, however, came Ulysses in the guise of a merchant, and he spread his wares before the royal household,--jewels and ivory, fine fabrics, and curiously wrought weapons. The king's daughters chose girdles and veils and such things as women delight in; but Achilles, heedless of the like, sought out the weapons, and handled them with such manly pleasure that his nature stood revealed. So he, too, yielded to his destiny and set out to join the heroes. Everywhere men were banded together, building the ships and gathering supplies. The allied forces of Greece (the Achaians, as they called themselves) chose Agamemnon for their commander-in-chief. He was a mighty man, king of Mycenæ and Argos, and the brother of the wronged Menelaus. Second to Achilles in strength was the giant Ajax; after him Diomedes, then wise Ulysses, and Nestor, held in great reverence because of his experienced age and fame. These were the chief heroes. After two years of busy preparation, they reached the port of Aulis, whence they were to sail for Troy. But here delay held them. Agamemnon had chanced to kill a stag which was sacred to Diana, and the army was visited by pestilence, while a great calm kept the ships imprisoned. At length the oracle made known the reason of this misfortune and demanded for atonement the maiden Iphigenia, Agamemnon's own daughter. In helpless grief the king consented to offer her up as a victim, and the maiden was brought, ready for sacrifice. But at the last moment Diana caught her away in a cloud, leaving a white hind in her place, and carried her to Tauris in Scythia, there to serve as a priestess in the temple. In the mean time, her kinsfolk, who were at a loss to understand how she had disappeared, mourned her as dead. But Diana had accepted their child as an offering, and healing came to the army, and the winds blew again. So the ships set sail.