In order to understand Creon's law in Sophocles' Antigone, we must first examine the events that occurred before the start of the play.
Oedipus was once the ruler of Thebes. Creon takes over as king until Oedipus' sons, Polynices and Eteocles, come of age.
When the sons are old enough to rule, Eteocles claims the throne for himself, despite the fact that his brother is older and should be first in line to be king. Eteocles names himself king and banishes his brother from Thebes.
In response to his brother's actions, Polynices raises an army and attacks his native city. A civil war ensues, and the two brothers kill each other in battle.
This is when Creon's law goes into effect. Creon decrees that Eteocles is to be buried properly and with full honors, because he died defending Thebes. Polynices, on the other hand, is now considered a traitor because he attacked Thebes. Creon states that Polynices is to be left unburied on the battlefield, where he will be exposed to the elements and animals. He also says that anyone who attempts to bury Polynices's body will be put to death.
Creon's law sets the plot of Antigone into motion.