In Euripides's play The Phoenician Women, Jocasta, the mother and wife of Oedipus, says that their sons, Eteocles and Polynices have imprisoned Oedipus in the palace. They have done this to hide him, and his shame, from the world. The brothers decided to share power in annual succession because Oedipus called down curses open them, praying that they would destroy one another, and they were afraid these curses might be fulfilled if they stayed together.

Jocasta says that her son has married the daughter of King Adrastus of Argos, and she tells him that this foreign marriage has caused her pain and is a heavy blow to the entire family. Polynices replies that he married in exchange for the promise of an Argive army from Adrastus (which he has now brought with him) to wrest power from Eteocles in Thebes.

Eteocles says that he is unwilling to yield to his brother's wishes, first because only a coward would give up a kingdom, thereby exchanging the highest mortal state for a lower one, and because Polynices is threatening the city with an army, and it would also be cowardly to give in to such a threat. The brothers eventually pledge that when Polynices attacks the city, they will stand directly against, each other at the same gate, and fight.

Creon arrives to tell Eteocles that a prisoner has escaped from the Argive camp, bringing news of their strategy. They will be storming the seven gates of Thebes simultaneously with seven companies of men. Creon encourages Eteocles to appoint seven co-commanders, each of who can act autonomously to defend one of the gates, since one leader will never be able to see everything that is occurring on the battlefield. Finally, Teiresias says that the only way to save Thebes is to appease the gods with the blood-sacrifice of Creon's son, Menoeceus.