The hero at once went away from Troy, but not without resolving to return at a convenient time and punish Laomedon. This he did, not long afterwards, when he had completed the celebrated "twelve labors" at which he had been set by a Grecian king, whom Jupiter commanded him to serve for a period of years because of an offense he had committed. One of these labors was the killing of the lion. Another was the destroying of the Lerʹnæ-an hydra, a frightful serpent with many heads, which for a long time had been devouring man and beast in the district of Lerʹna in Greece. Having accomplished his twelve great labors and ended his term of service, Hercules collected an army and a fleet, and sailed to the shores of Troas. He then marched against the city, took it by surprise, and slew Laomedon and all his sons, with the exception of Po-darʹces, afterwards called Priam. This prince had tried to persuade his father to fulfill the engagement with Hercules, for which reason his life was spared. He was made a slave, however, as was done in ancient times with prisoners taken in war. But Hesione ransomed her brother, giving her gold-embroidered veil as the price of his freedom. From this time he was called Priam, a word which in the Greek language means "purchased." Hesione also prevailed upon Hercules to restore Priam to his right as heir to his father's throne, and so he became king of Troy. Hesione herself was carried off to Greece, where she was given in marriage to Telʹa-mon, king of Salʹa-mis, a friend of Hercules. Priam reigned over his kingdom of Troas many years in peace and prosperity. His wife and queen, the virtuous Hecʹu-ba, was a daughter of a Thracian king. They had nineteen children, many of whom became famous during the great siege. Their eldest son, Hecʹtor, was the bravest of the Trojan heroes. Their son Parʹis it was, as we shall see, who brought upon his country the disastrous war. Another son, Helʹe-nus, and his sister Cas-sanʹdra, were celebrated soothsayers. Cassandra was a maiden of remarkable beauty. The god Apollo loved her so much that he offered to grant her any request if she would accept him as her husband. Cassandra consented and asked for the power of foretelling events, but when she received it, she slighted the god and refused to perform her promise. Apollo was enraged at her conduct, yet he could not take back the gift he had bestowed. He decreed, however, that no one should believe or pay any attention to her predictions, true though they should be. And so when Cassandra foretold the evils that were to come upon Troy, even her own people would not credit her words. They spoke of her as the "mad prophetess." Cassandra cried, and cursed the unhappy hour; Foretold our fate; but by the god's decree, All heard, and none believed the prophecy. VERGIL.