'Heir to the throne'? *headdesk* There's a reason I've never rewatched this movie. Though I am glad it existed because they cleaned part of the Colosseum Flavian Ampitheater for it.

But even in the later empire and the early eastern empire they were still using 'princeps' and flattering epithets, rather than anything else. I don't know when/if the Byzantines changed that. I should go read that book I have about the 8thC Byzantine empresses, maybe it will tell me.