Final answer:
In the play 'Oedipus Rex', King Oedipus is on the throne when Thebes is attacked. The attack on Thebes is a central plot point in the play.
Step-by-step explanation:
In the play 'Oedipus Rex', King Oedipus is on the throne when Thebes is attacked. The play opens with Oedipus trying to find a remedy for a terrible plague that is decimating his people. In order to lift the plague, he must find and punish the killer of the previous king of Thebes. This sets off a chain of events that leads to the downfall of Oedipus and the attack on Thebes.