Sophocles
Oedipus eventually learns of the Delphic Oracle's prophecy of him. It was: he would kill his father and marry his mother. He thought this meant his adopted parents. He flees to avoid his fate. Oedipus meets a man at a crossroads accompanied by servants. Oedipus and the man fight, and Oedipus kills the man. This man was his father, Laius, not that anyone apart from the gods knew this at the time.