The action of the play begins in 169 BC, 22 years after Antiochus's defeat in the Battle of Thermopylae. (The historical Antiochus III died in 187). As the first scene opens, Antiochus is approaching the city of Carthage, accompanied by the Stoic philosopher who is his counsellor, and three servants. After living concealed and in obscurity since the battle, Antiochus is now trying to regain his lost crown; he has come to Carthage, a traditional enemy of Rome, in search of support. He discusses his thoughts and feelings with the philosopher.