As is the case in most climactic drama, much of what constitutes the myth of Oedipus takes place before the opening scene of the play. In his youth, Laius was a guest of King Pelops of Elis, and became the tutor of Chrysippus, youngest of the king's sons, in chariot racing. He then violated the sacred laws of hospitality by abducting and raping Chrysippus, who according to some versions, killed himself in shame. This murder cast a doom over Laius, his son Oedipus, and all of his other descendants. However, most scholars are in agreement that the seduction or rape of Chrysippus was a late addition to the Theban myth.
A son is born to King Laius and Queen Jocasta of Thebes. After Laius learns from an oracle that "he is doomed/To perish by the hand of his own son", he tightly binds the feet of the infant together with a pin and orders Jocasta to kill the infant. Hesitant to do so, she orders a servant to commit the act for her. Instead, the servant takes the baby to a mountain top to die from exposure. A shepherd rescues the infant and names him Oedipus (or "swollen feet"). (The servant directly hands the infant to the shepherd in most versions.) The shepherd carries the baby with him to Corinth, where Oedipus is taken in and raised in the court of the childless King Polybus of Corinth as if he were his own.
As a young man in Corinth, Oedipus hears a rumour that he is not the biological son of Polybus and his wife Merope. When Oedipus questions the King and Queen, they deny it, but, still suspicious, he asks the Delphic Oracle who his parents really are. The Oracle seems to ignore this question, telling him instead that he is destined to "Mate with [his] own mother, and shed/With [his] own hands the blood of [his] own sire". Desperate to avoid his foretold fate, Oedipus leaves Corinth in the belief that Polybus and Merope are indeed his true parents and that, once away from them, he will never harm them.
On the road to Thebes, he meets Laius, his true father, with several other men. Unaware of each other's identities, Laius and Oedipus quarrel over whose chariot has right-of-way. King Laius moves to strike the insolent youth with his sceptre, but Oedipus throws him down from the chariot and kills him, thus fulfilling part of the oracle's prophecy. He kills all but one.
Shortly after Oedipus solves the riddle of the Sphinx, which has baffled many diviners: "What is the creature that walks on four legs in the morning, two legs at noon, and three in the evening?" To this Oedipus replies, "Man" (who crawls on all fours as an infant, walks upright later, and needs a walking stick in old age), and the distraught Sphinx throws herself off the cliffside. Oedipus's reward for freeing the kingdom of Thebes from her curse is the kingship and the hand of Queen Dowager Jocasta, his biological mother. The prophecy is thus fulfilled, although none of the main characters knows it.