It struck me that this felt like a combination of “The Man in the Iron Mask” and “The Decline and Fall of the Roman Empire.” Following Marcus Aurelius's death, his son Commodus (played by Mimmo Palmara) takes over and immediately begins a period marked by gladiatorial contests alongside large-scale theft and acts of violence. However, he doesn’t know that a twin brother was hidden at birth by senator “Tarrunio” (Gianni Solaro), who then gave him the name "Lucius" (Richard Harrison). With his Praetorian prefect “Leto” (Alberto Farnese) causing trouble in Rome, it appears only his lover “Marcia” (Moria Orfei) might be able to control the new emperor. But when he gives her away as a cruel punishment, the responsibility falls on the older senator to summon the twin brother, hoping that together they can get rid of the tyrant before unrest destroys the city. There's a lot happening in this film, with numerous gladiatorial fights, sword battles, and action sequences that keep the story moving quickly for much of its final hour. While the actors portraying the twins don’t really look alike, which felt a little unbelievable at times, it didn’t ultimately detract from the film’s generally enjoyable feel.

Source on TMDB