Gladiator story?

was there any truth to the story of the movie?
i dont think there is but, its possible

Not really, no. Clearly you didn’t stay and read the credits. At the end it says something like:

Gave me kind of a laugh. Like there are any known descendants of Commodus who are gonna sue for libel…

It’s a remake of “The Fall of the Roman Empire”, more or less. See:
http://us.imdb.com/Details?0058085
There is some historical truth to the history (Marcus Aurelius and Commodus) but the story itself is fictional.

It also owes some debt to “Spartacus”. See:
http://us.imdb.com/Details?0054331
Although the real Spartacus episode happened a good deal earlier.