All went well for many years until a plague struck Thebes. People, crops, and animals were dying. Desperate to learn the cause, Oedipus sent Jocasta's brother, Creon, to consult the great oracle at Delphi.
The oracle warned that the plague would not end until Thebes had punished the murderer of King Laios, who lived among them undetected. Oedipus vowed to save Thebes once again by finding this murderer.
After questioning several people, including the blind prophet Teiresias, he discovered that the man he had killed on the road years before was none other than King Laios. Furthermore, he learned that he was not the son of the king and queen of Corinth, but rather the son of Laios and Jocasta. Thus Oedipus had in fact fulfilled the oracle's prophecy-he had killed his father and married his mother.
When Oedipus and Jocasta discovered this horrible truth, she killed herself and he gouged out his eyes to punish himself for having been blind to the truth. After these disasters, Creon took over as regent (acting ruler) of Thebes, and after several years he decided to exile Oedipus. Accompanied only by his daughter Antigone, Oedipus wandered the countryside as a beggar until he reached the sanctuary of Colonus, where he died.
Antigone returned to Thebes, where her two brothers had agreed to rule in alternate years. Eteocles' turn came first, but when it ended, he refused to give up his throne to Polyneices.
Polyneices fled to the city of Argos, where he raised an army; he then returned with his men and attacked the seven gates of Thebes.