It was when Oedipus the King and his wife Jocasta, the past wife of the former King Laius, ruled the Kingdom of Thebes.
People begged Oedipus to save the kingdom since Oedipus became their king because he was able to free them from the sphinx.
The kingdom have been affected by a plague and everything was in catastrophe due to this.
Oedipus assured people of his service ,since for him what worries his people, also worries him.
As a resolution of Oedipus to the plague, he sent Creon, brother of Jacosta, to the God of truth, Apollo.
Through this, they will be able to know the cure of the said plague and hence will save everyone in the kingdom.
He conditioned that if he will find the murderer, he will exile it from their kingdom.
Creon came back saying that according to Apollo, the cure for the plague is the blood of the man who's guilty of the murder of King Laius.
Oedipus believed that they will be able to find the guilty as soon as possible since it said that it is within the kingdom. He decided to start the search.
Oedipus asked the help of Tiresias, a blind prophet that is known to be wise for truths.
Oedipus got furious and accused Tiresias and Creon that they were planning everything to replace him from the throne.
But Tiresias said things that pointed out Oedipus to be the killer of King Laius.
Oedipus ordered Tiresias to get out of his sight and never show himself to him ever again.
Creon confronted Oedipus when he learned his accusations of him conquering Oedipus' throne.
Although, Jocasta convinced Oedipus to believe Creon that there are no such intentions with Tiresias. Creon even othed himself for proof.
Jocasta told him to free himself from such thoughts for the reason that Kiing Laius had a prophecy. He was told that he was going to die by his own son's hand. Oedipus then also explained his prophecy that he was destined to kill his father and marry his mother.
Jocasta talked to Oedipus about their confrontation and Oedipus explained that Creon was pointing him as the murderer of king Laius.
With these prophecies of Oedipus, that made him decide to leave his known parents' kingdom.