Answer:
In Sophocle's "Antigone," Antigone and Ismene are sisters, daughters of the ill-fated Oedipus.
At the begining of the play the are discussing Creon's orders to not give Polynices, one of their two dead brothers, a propoer burial.
After Oedipus' death, it was agreed that both of his sons, Eteocles and Polynices, would take the throne from one year to the next. However, when Eteocles refused to give up the throne, Polynices joined forces with other foreign princes and attacked Tebes.
Both brothers were killed during the fight but, considering his actions as treason, Creon, as acting king, declared that only Polynices would be given a proper burial.
Textual evidence
ANTIGONE:
Listen, Ismene: Creon buried our brother Eteocles with military honors, gave him a soldier’s funeral, and it was right that he should; but Polyneices, they fought as bravely and died as miserably. They say that Creon has sworn no one shall burry him, no one mourn for him, but this body must lie in the fields, a sweet treasure.
(Sophocles, Antigone, Prologue v.15-20)