He then went on through Bœotia.  On the top of a hill near Thebes sat a monster called the Sphinx, with a women’s head, a lion’s body, and an eagle’s wings.  She had been taught riddles by the Muses, and whoever failed to answer them she devoured upon the spot.  Whoever could answer her was to marry the king’s sister, and share the kingdom.  Œdipus went bravely up to her, and heard her question, “What is the animal that is at first four-legged, then two-legged, then three-legged?”  “Man,” cried Œdipus.  “He creeps as a babe on all-fours, walks upright in his prime, and uses a staff in his old age.”  Thereupon the Sphinx turned to stone, and Œdipus married the princess, and reigned many years, till there was a famine and pestilence, and the oracle was asked the cause.  It answered that the land must be purified from the blood of Laius.  Only then did Œdipus find out that it was Laius whom he had slain; and then, by the marks on his ancles, it was proved that he was the babe who had been exposed, so that he had fulfilled his fate, and killed his own father. To save Thebes, he left the country, with his eyes put out by way of expiation, and wandered about, only attended by his faithful daughter Antigone, till he came to Athens, where, like Orestes, he was sheltered, and allowed to expiate his crime.  After his death, Antigone came back to Thebes, where her two brothers Eteocles and Polynices had agreed to reign each a year by turns; but when Eteocles’ year was over he would not give up to his brother, and Polynices, in a rage, collected friends, among whom were six great chiefs, and attacked Thebes.  In the battle called “The Seven Chiefs against Thebes,” all were slain, and Eteocles and Polynices fell by each other’s hands.  Their uncle Creon forbade that the bodies of men who had so ruined their country should receive funeral honours from anyone on pain of death, thus condemning their shades to the dreary flitting about on the banks of the Styx, so much dreaded.  But their sister Antigone, the noblest woman of Greek imagination, dared the peril, stole forth at night, and gave burial alone to her two brothers. She was found out, and put to death for her sisterly devotion, though Creon’s own son killed himself for grief and love of her.  This happened in the generation before the Trojan war, for Tydeus, the father of Diomed, was one of the seven chiefs.