The myth of Oedipus revolves around a man destined by the gods to suffer the most horrible fate. Oedipus' story takes place, for the most part, in the city of Thebes in northern Greece, where he was born. When he was still in his mother's womb, Oedipus' parents Laius and Jocasta asked the oracle of Apollo at Delphi about their unborn child. The oracle's reply was terrifying, that the boy would grow up to marry his mother and kill his father.

Because of this horrifying portent, Jocasta and Laius did what many people with unwanted children did in antiquity. They had the baby's feet spiked—Oedipus' name means in Greek "swollen foot," the result of this injury—and ordered a faithful herdsman who worked in the mountains near Thebes to carry the child off into the wild and abandon it, an act called exposure. With this, they thought they had sidestepped fate but, in fact, their actions proved to be part of its unfolding.

The herdsman felt pity for the helpless babe so, instead of leaving it to rot in the wild or serve as fodder for wild animals, he handed it over to another herdsman from the neighboring city of Corinth. This man, in turn, gave it to his king and queen, Polybus and Merope, who were childless and raised Oedipus as their own. Thus, the boy grew up in Corinth believing himself the natural-born offspring of the royal family, until one day when he heard from a visiting stranger that he wasn't the legitimate son of Polybus and Merope. After his parents refused to tell him one way or the other, Oedipus stormed off to Delphi to demand the truth of Apollo. As before, the oracle delivered its gruesome verdict on his fate.

Stunned by the revelation that he was destined one day to marry his mother and kill his father, he vowed never to return to Corinth but instead headed down a different road leading out of Delphi and ended up eventually near Thebes. As he approached the city, he came to an intersection where three roads converged, and encountered there an old man riding along the path who refused to give way. Their quarrel quickly escalated to violence, and in the primordial act of road rage he knocked the obstructive gaffer out of his wagon, killing him.

When he reached Thebes, Oedipus discovered a city under siege. A horrendous monster called the Sphinx ("Strangler") was choking the city off from the rest of the world. It refused to let anyone pass who couldn't answer its riddle: "What walks on four legs in the morning, two legs at noon, and three in the evening?" Being naturally quick-witted, Oedipus figured out that the answer was Man, who crawls when young, walks upright as an adult and uses a cane in old age. In shock and rage, the Sphinx threw itself off a cliff.

Oedipus entered Thebes a triumphant savior, winning both throne and queen. His wife was, of course, the newly widowed Jocasta, and as was later revealed, his own mother. When the full truth about Oedipus' birth at long last came to light and she realized that through her actions her son-and-husband had committed unspeakable acts, Jocasta killed herself. Soon thereafter, blinded and forlorn, Oedipus went into exile from Thebes. So goes Sophocles' version of the myth.

But that's not the only incarnation of this legend in ancient literature. To appreciate Sophocles' play fully, it's necessary to experience it the way the ancient audience did, knowing no more about the plot than what the audience at the premiere entered the Theatre of Dionysus knowing. And that was probably somewhat less than the story above, only the basic skeleton of a myth in which a powerful Theban king named Oedipus turned out to be responsible for what was to the ancients, no doubt, the most horrific crimes imaginable. But most likely they didn't know how, when and why Oedipus did what he did, because the details of any story told on the Greek stage were at the individual playwright's discretion whose originality and genius were measured in the way he deployed those particulars.

The same was indeed true of all Greek myths and dramas. Contrary to common opinion, ancient Greek tragedians were free to add elements into a story or alter the plot as long as they stayed within the general parameters outlined in the traditional version of a myth. That is, as long as Oedipus killed his father and married his mother, the playwright could, for the most part, sculpt the story his own way. In this case, there's evidence Sophocles has designed a remarkably inventive, indeed revolutionary approach to the standard way the myth of Oedipus ran in his day.

We get some sense of this from earlier versions of the myth. In the age before Sophocles, Aeschylus had written dramas based on Oedipus' life. Unfortunately, only the final play of Aeschylus' trilogy about Laius' family and offspring survives, and that tells us remarkably little about the first two in which Oedipus' story played out. Nevertheless, it seems safe to say the Aeschylean Oedipus was a rather unsavory character who clung to power despite the gods' clear enmity.

Long before Aeschylus even, Homeric audiences evidently listened to the tales of Oedipus' woes. While the full story of his tragedy doesn't appear in Homer as such or in any surviving text of Greek epic, the oral bard recapitulates the myth briefly when Odysseus visits the Underworld and sees Oedipus' mother and wife Jocasta, whom he calls Epicaste, among the ghosts of the dead (Odyssey 11.271-80):

So, according to Homer, Oedipus lived out his "evil days" in Thebes even after the revelation of his great crime. The epic tradition suggests, in fact, he died there (Iliad 23.678-80):

Several of the details included here directly contradict the story of Oedipus as Sophocles tells it, which shows the variability allowable in Greek myth. Nevertheless, the general theme of parricide and incest remains at the core of the tale.

Another character who appears often in this myth and whom the classical Athenian audience, no doubt, came into the theatre expecting to see in Sophocles' play was Jocasta's brother Creon ("King"). The latter, according to tradition, ruled Thebes during the brief transitional period between the mysterious disappearance of Laius and Oedipus' arrival, at the time when the Sphinx was besieging the city. But that is probably all the viewers came into the theatre expecting, the basic framework of a tale in which the king of Thebes marries his own mother and kills his father and she commits suicide when the truth comes out.