Trivia: Alec Guinness plays Marcus Aurelius, the father of Commodus (Christopher Plummer). In real life, Guinness was only 15 years older than Plummer.
Trivia: While the "auction" to choose a new emperor actually did occur, it did not happen immediately after the death of Commodus, but after the death of Pertinax, Commodus' immediate successor.
Trivia: The reconstruction of the Roman Forum at Las Matas for this film holds the record for the largest outdoor film set ever constructed. The various ancient Rome settings covered 55 acres.
