Dramatic irony occurs when a character in the play speaks in a manner that indicates he or she is unaware of other circumstances of which the audience is aware. In Scene 3 of Sophocles's Antigone, King Creon speaks to his son Haemon, who is engaged to Antigone, telling him,

Therefore, rulers must be
supported, and we must not yield to women.
It would be better, if it had to be,
to fall at a man's hands and not to be called
worse than a woman. (687-691)

The audience knows that Antigone has buried her brother and that Creon will probably be defeated by her determination because she obeys the law of god.

Another example of dramatic irony occurs in one of the final scenes as the blind prophet Teiresias predicts the ruin of Thebes. But Creon retorts,

But, the cleverest
of mortals, old Tiresias, fall with shameful
crash, when they decorate shameful words
for the sake of profit. (1051-1054)

Unfortunately for Creon, he is unaware that he is describing himself; for, he suffers a tragic fall in the end as he realizes that his prideful actions against Antigone have precipitated the deaths of his son and wife.