A terrible, dissolute, reckless emperor, hardly worthy to be the successor of the great Antonine, Marcus Aurelius. Note: if you saw the movie Gladiator, Commodus did NOT die in the gladiatorial ring; he was assassinated by a conspiracy of his guards; he did, however, occasionally fight in the ring. There is no evidence that he killed his father--this is an invention of the movie--Marcus Aurelius died of a fever, possibly typhus, while in an army camp near modern-day Vienna.
