The association of "ruling class" and colonisation is part of it. hyperallergic.com/94...

Why Do We Expect Ancient Romans to Have British Accents in Movies?

Most of the objectors to Denzel Washington’s accent are men who think too much about the Roman Empire. Here’s how the accent has changed throughout cinema.

I was surprised when I first heard Crown Princess Victoria of Sweden speaking English. She has an American accent. You kind of expect royalty to sound like the Sachsen-Coburg und Gotha gang. That’s why ’The Broon Windsors’ is funny.

In the film adaptation of “Eagle of the Ninth”, the Brits had British accents and the Romans American accents. That had some quite interesting resonances.