The first time I noticed a historical adventure-romance in which the lead male character (and only the lead male character) spoke in a glib and casual modern-American manner was Richard Donner‘s Ladyhawke (’85). The critically-despised Warner Bros release was set in 12th Century Europe and Matthew Broderick — 22 or 23 at the time of filming — played Phillippe Gaston, a ne’er-do-well who used the attitude and idioms of Ferris Bueller.
The idea, obviously, was to make 1985 audiences feel more comfortable within an exotic milieu by offering one of their own as a guide. It’s totally standard practice now, but back then (27 years ago!) it was a relatively new way to go.
It could be argued that Tony Curtis did the same thing in Son of Ali Baba (’52) by speaking in a New York accent while saying lines like “this is the palace of my father, and yonder lies the Valley of the Sun.” (Curtis was unfairly chided for allegedly mouthing a similar-sounding line, “Yonda lies the castle of my foddah”, in The Black Shield of Falworth (’54)…which in fact he never said.)
But Curtis, one could further argue, was at least trying to muffle his borough accent and lend as much historical realism as possible, or at least not flaunt the fact that he was a 1950s actor who’d been raised in the Bronx. Ladyhawke‘s Broderick, by contrast, emphasized his Ferris Bueller-ness. The point was to sound like a wise-ass mall rat transported to medieval times by a time machine.
James Franco, portraying Oscar Diggs in the 19th Century realm of Oz, The Great and Powerful (Disney, 3.8), talks as if like he’s backstage at the Oscars or hanging in his trailer while shooting Spring Breakers or chatting with Jon Stewart on the Daily Show. Exclamations like “I don’t want to die…I haven’t accomplished anything yet!” tell the under-35 sophistos they won’t have to adjust to a damn thing, that Oz won’t challenge them in the slightest.