Seven against Thebes
Right after the exile of King Oedipus to mountain Kolonos, his son Eteocles became the new king for a predefined period of one year. His brother Polynices was supposed to take the throne, when the year passed but Eteocles refused to pass the authority to his brother. Polynices left Thebes and found refuge to the city of Argos in the palace of king Adrastos. He married Adrastos daughter and prepared a military campaign against Thebes, in order to gain the throne he deserved. The troops of Argos have been leaded by seven generals (Polynices included) (the tragedy was named after them : seven against Thebes).
Eteocles had sent a spy to Argos to get information about the enemy plans. The spy returned and reported to his king about the campaign. Eteocles prepares the defense of Thebes, addressing one warlord for each one of the seven gates of the city (he had kept one for himself). In the battle he fought against his brother. The army of Thebes won the battle but both Eteocles and Polynices died.
Kreon, their uncle took over the throne of Thebes and the prophecy about the horrible fate of the family of Laios has come true.