Not in the underrated movie The Eagle! In that one, the soldier from the world's dominant global empire has an American accent, and the actual Briton slave has a British accent.
I should watch that one. Not that surprising since it's a British film. There's also Waterloo which cast English as English, Scottish as Scottish, French as American, and German as idk foreign, plus tons of extras either yelling in French or saying nothing in Russian.
And of course there's Death of Stalin where everybody just uses either their own accent or they're Jason Isaacs who went for over the top Yorkshire.
I love creative accent work in movies. I recently watched Pride and Prejudice, and Donald Sutherland clearly isn't doing an English accent but it works somehow.
It's probably because anything set in ancient or medieval times in American film uses British accents. You'll seen it for Rome, Sparta, Macedonia, and even Persia.
