As SL said, “Gladiator” was entertaining, but not historical, even though the names of some of the characters were real. I read (probably in an Amazon review) that the movie was basically a high-end remake of a gladiator flick from about 1960.
The real Commodus had his sister exiled to Capri (I’m kinda jealous of that exile) but after she got there, she was executed.
Of course, we need to realize that Hollywood doesn’t make documentaries, at best it makes crockumentaries.