In this, the only extant tragedy from Aeschylus' trilogy about the House of Oedipus, Thebes is under siege from Polynices, a former prince of Thebes. After King Oedipus left his city and cursed the princes, Polynices and his brother, Eteocles, decided to rule alternately, switching at the end of every year. However, at the end of his year as king, Eteocles refused to turn power over to his brother and exiled him, fulfilling his father's curse that the two brothers could not rule peacefully. In the action of the play, Polynices and a group of Argive soldiers are attacking Thebes so that he can take his place as ruler. Eteocles must combat both the foreign forces outside the walls and the crazed, frightened women within. Note: The ending of this play is suspect. The lines Antigone and Ismene's entrance to the end may have been added later, either after Sophocles' Theban plays became popular or in the Middle Ages.