Oedipus Rex and that deal with the story of Oedipus, "Oedipus Rex" was the second to be written. However, in terms of the chronology of events that the plays describe, it comes first, followed by "Oedipus at Colonus" and then "Antigone". Prior to the start of "Oedipus Rex", Oedipus has become the king of Thebes while unwittingly fulfilling a prophecy that he would kill his father, Laius (the previous king), and marry his mother, Jocasta (whom Oedipus took as his queen after solving the riddle of the Sphinx). The action of Sophocles' play concerns Oedipus' search for the murderer of Laius in
Oedipus Rex of the Delphic Oracle. He visits Delphi to find out who his real parents are and assumes that the Oracle refuses to answer that question, offering instead an unrelated prophecy which forecasts patricide and incest. Oedipus's assumption is incorrect, the Oracle does, in a way, answer his question: "On closer analysis the oracle contains essential information which Oedipus seems to neglect." The wording of the Oracle: I was doomed to be murderer of the father that begot me refers to Oedipus' real, biological father. Likewise the mother with polluted children is defined as the biological one. The wording of the