Answer:
It means that Polynices and Eteocles, who believed they were destined to conquer Thebes, ended up killing each other, without conquering anything.
Step-by-step explanation:
The question above refers to the story of Polynices and Eteocles who were sons of Oedipus.
Both had the desire and believed that they were destined to conquer and dominate Thebes and because of that desire, they disrespected anyone including their father Oedipus. When Oedipus was disrespected, he prayed to Zeus that his children would be punished and die without achieving their goals. Thus, Zeus in conflict with Ares, the god of war, did not allow either of Oedipus' two sons to conquer Thebes and even caused one to kill the other.