Myth: Commodus Killed Marcus Aurelius

"Commodus killed Marcus Aurelius" is a wild rumor that’s been picked up by screenwriters. For example Commodus participates in the death of Marcus Aurelius in “The Fall of the Roman Empire”. And since Ridley Scott’s “Gladiator” in many ways was inspired by “The Fall of the Roman Empire”, this interesting plot twist traveled to his movie as well.

Let's find out how this idea sits with the original sources and common sense.