Prior to the opening of Sophocles's Antigone, two brothers, Polynices and Eteocles, kill each other in battle. Creon decides that Polynices's body is to be left unburied on the battlefield; anyone who tries to bury him will be put to death. Eteocles, on the other hand, is given a proper burial with honors. To understand the difference in Creon's treatment of the brothers, we must examine why they fought.
Oedipus, father of Polynices and Eteocles, once ruled as king of Thebes. Creon took over as interim king until Oedipus's sons are old enough to rule.
When the brothers were of ruling age, Eteocles claimed the throne for himself, even though he was the younger of the brothers and was not next in line to rule. He exiled Polynices.
In response, Polynices gathered an army of outside forces and attacked his native city, Thebes. The two brothers ended up killing each other in the midst of the battle.
Polynices is now considered a traitor, because he attacked his own city. Because of this betrayal, Creon decrees that he will not be given a burial. His body is left on the battlefield for the elements and animals to destroy.
Eteocles, on the other hand, is considered a hero, because he died defending his native Thebes. Creon therefore allows him to be properly buried, with honors.