Emma Stone was "shocked" when she discovered how "violent and sexual" British royal history is whilst working on 'The Favourite'.
The 29-year-old actress stars as Baroness Abigail Masham in the upcoming drama film that centres around the court of Queen Anne (played by Olivia Coleman) in the early 18th century, and has said she and her fellow co-stars were "mutally shocked" to discover the history behind the British royals.
She said: "[We were] mutually shocked. Your royal history wasn't so picture perfect! Henry VIII beheaded his wives. And there were certainly things going on during other reigns that were violent and sexual."
The film focuses on Emma's character and her on-screen cousin Sarah Churchill, Duchess of Marlborough, played by Rachel Weisz, as they engage in a bitter rivalry to become court favourites of Queen Anne.
And in order to get them prepared for their roles, director Yorgos Lanthimos allowed the trio to get up to some raucous antics, which Emma found an "interesting" way to get close to her co-stars.
She added: "It was a unique rehearsal process, where we were being ridiculous with each other ... for two weeks. It was an interesting way to learn that we'd be safe with each other."
Emma wouldn't divulge any further details on the antics, but director Yorgos insists the characters in the movie are "complex and complicated" roles to take on.
He said: "[These characters are] complex and complicated, and at any given time in the film they can be doing things you don't necessarily expect from them."
The movie was partly adapted from things referenced in the scholarly biographies of the late monarch, but Yorgos admits some things were added for dramatic effect, including the decision to give Anne one pet rabbit to represent every child of hers that died.
Speaking to the Daily Mail newspaper, he said: "I've forgotten some of the things we invented. Except Anne didn't really have any rabbits.
"We tried to make these women not one-dimensional, and you understand that they've been through a lot - and then go through a lot more."