"Seven Against Thebes" is the third and only surviving play from a tetralogy Aeschylus entered in the Great Dionysia. The tetralogy follows the cursed Theban patriarchy headed by Laius--the focus of the first tragedy--his son Oedipus--the focus of the second tragedy--and Oedipus's sons, Eteocles and Polyneices, featured in "Seven Against Thebes". Eteocles, the reigning King of Thebes, must defend his city against his own brother Polyneices, who, in concert with Adrastus, the King of Argos, plans to invade Thebes and claim the throne. Before battle, the seven invading captains choose lots to determine which of the seven Theban gates to attack. A messenger delivers each announcement to Eteocles, who sends one of his own men to defend the gate. The last announcement names Polyneices as the final invading captain, pitting him against his own brother, Eteocles. The two brothers take up arms against each other and both are killed during the successful defense of the city.