When Oedipus's crimes were revealed he was expelled from Thebes (or withdrew), and rule passed to his sons Eteocles and Polynices. In the epic Thebaid tradition the brothers incur their father's curse by serving him from Cadmus's forbidden silver table and golden cup, and by sending him the wrong portion of a sacrifice; Oedipus prays that they will die by each other's hands.

In Sophocles's Oedipus at Colonus, Oedipus is driven out by Creon; the sons quarrel over the throne, Eteocles wins Theban support and expels Polynices, who seeks a blessing to retake the city and instead receives a curse of mutual death.

Accounts of the succession differ. Hellanicus has Eteocles offer Polynices a choice between the kingship and a share of property. Pherecydes has Eteocles expel Polynices by force. Apollodorus and Diodorus say the brothers agreed to alternate the kingship yearly; Eteocles took the first year and refused to yield.

Polynices then gathered Argive allies and attacked Thebes in the war of the Seven against Thebes, the subject of Aeschylus's Seven Against Thebes. The Thebans held the city, but the brothers slew each other. Creon buried Eteocles with honor and denied burial to Polynices — the edict Antigone defies.

Upon Eteocles's death Creon ruled as successor (or as regent for Eteocles's son Laodamas). The next generation — the Epigoni — later returned and took Thebes, completing the cycle begun by the brothers' broken pact and their father's curse.

Eteocles stands in tragedy as the brother who holds the city: defender of Thebes in Aeschylus, yet also the ruler whose breach of the power-sharing agreement launches the war that destroys his house.