Sins of the Father
This play is a continuation of the story of Oedipus, the King of Thebes, who learned that he married his mother and had children with her. His sons would be cursed by their father to divide the kingdom between them through bloodshed. Thus, Eteocles and Polynices killing each other fulfills the curse that began with their father.
Defiance
Eteocles has defied his agreement with his brother Polynices to rule in alternate years, he instead is willing to go to war to keep his power from transferring to his brother. Another act of defiance is seen in Antigone, sister to the two slain brothers. She defies the edict that an enemy of Thebes is not allowed a proper burial, the people of the city are set on leaving Polynices' body to be eaten by dogs; but she is determined to bury her brother in defiance of the edict.
Betrayal
Betrayal is a central theme of the play. Eteocles first betrays his brother Polynices by not holding to their agreement to rule Thebes in alternating years, and because of this Polynices forms an army to take the city. Polynices' actions are seen as a betrayal of his people as he is the only man of Thebes that stands in opposition to Eteocles and thus is considered to be not only betraying his brother, but his city and its people.
