Their father, Oedipus, had previously murdered his father Laius and married his mother Jocasta without anyone knowing the relationship between them. When it was all revealed, Oedipus was expelled from the city and the rule passed to his sons, Eteocles and Polynices. However, Oedipus was furious at them for treating him disrespectfully in the past and cursed them to die by each other's hands. Due to the curse, the shared rule was not particularly smooth. Eteocles ended up taking the throne for himself and forcibly sending Polynices away from Thebes. Polynices, angry at his brother, assembled an army and attacked the city; in the battle that followed, both brothers died, fulfilling their father's curse. Eteocles was buried with honours in the city, but his brother, considered a traitor, was left to rot on the battlefield. His sister, Antigone, later tried to bury him against the will of the newly appointed ruler, her uncle Creon, leading to further misery in the family.
Eteocles Is also called Eteoklis.