What does Oedipus learn about his birth during his conversation with Creon?

Oedipus learns critical information about his lineage and the circumstances surrounding his birth during his conversation with Creon. The dialogue reveals the tragic truth that he is not only the son of Laius and Jocasta, the former king and queen of Thebes, but also that he unknowingly fulfilled the prophecy that predicted he would kill his father and marry his mother. This conversation is pivotal, as it illuminates the tragic irony of Oedipus's situation; he had sought to escape his fate only to have his actions inadvertently lead him to fulfill it.

Understanding the full context of his origins is essential for Oedipus, as it forces him to confront his identity and the consequences of his past actions. His reaction to this revelation is a mixture of horror and despair, highlighting the themes of fate and free will that are central to the narrative of "Oedipus Rex." This understanding ultimately propels the narrative toward its inevitable and tragic conclusion.