Holy historical inaccuracies Batman! Who the hell is this character actually supposed to be? I named the page Augustus, because he was referred to as Caesar in the show (Caesar Augustus). There weren't too many Emperors of Rome that had that name. His father was a dictator, not emperor.
Caesar could just refer to the title, rather than a person's name, which would make it impossible to know for sure who it was.
The only other possibilities are Claudius and Nero, but if it is one of them, then the Colosseum shouldn't have been built yet. We could call it a mistake on the writers part but I think the name should be changed, since no name was given, we should just call him Caesar or Caesar, Emperor of Rome or something like that. Hell I don't know...pisses me off.