If you catch a glimpse of Claire Foy in the BBC’s A Very British Scandal, premiering April 22 on Prime Video, you might mistakenly think you’ve tuned in to an episode of Netflix’s The Crown. Because just as she did on The Crown, Foy stars on the new series as a real-life, privileged British woman who—while wearing smartly tailored skirt suits and showing impeccable manners— navigates public scrutiny in the 1960s.

A Very British Scandal centers around Margaret Campbell, neé Whigham, the late Duchess of Argyll, a woman lesser known to contemporary audiences in the States. “The difficulty with this [role] was that she actually was similar to [Elizabeth II], a character I’d been known for playing,” says Foy. “They were particular women at a particular period of time and with a particular background. The way they spoke, there is only so far you can go with that, really.… It was, for me, a bit dangerous as an actor, because there’s a lot of work I’ve got to do to not try and overplay the difference to try to make myself seem different.”

American audiences will quickly realize that the refined exterior is where the similarities between Campbell and Foy’s Queen Elizabeth end. Underneath Campbell’s icy façade is a sizzling personal life that would notoriously combust into scandal and tragedy—the messiness of which unspools in A Very British Scandal’s three parts.

Campbell was the gorgeous daughter of a self-made textile millionaire who cultivated her image in newspaper society pages. After a failed first marriage, she became the Duchess of Argyll when she married the duke Ian Campbell (played by Paul Bettany on the show) in 1951. The marriage was pocked with drinking, infidelity, lies, and a family fortune sunk into a Scottish castle. The couple’s consequent divorce trial, which was covered by flocks of press, would publicly define her. 

During legal proceedings, Ian provided a list of 88 men he suspected Margaret slept with during their marriage (including cabinet members, Hollywood actors, and members of the royal family), as well as private photos he had stolen that showed her performing oral sex on an unknown man whose head was out of frame.

The judge ended up ruling in the duke’s favor in 1963, chastising the duchess in a damning judgment that determined she was “a highly sexed woman who has ceased to be satisfied with normal sexual activities and has started to indulge in disgusting sexual activities to gratify a debased sexual appetite that can only be satisfied by a number of men.”

As Sarah Phelps, the writer who adapted Margaret’s story for A Very British Scandal, told Vanity Fair in a separate interview, “She was on trial for being a sexual woman.” Phelps noted that the judge described the photos in vivid detail during the three-hour-plus judgment, further humiliating Campbell—who was soon to become a grandmother—and making an example of her. “He took Margaret, hung a scarlet letter around her neck, and hung her out for the crowds to pick at her. If Margaret, Duchess of Argyll, gets away with this, what will all women do?”

Though the duchess was, by many accounts, a woman who enjoyed sex behind closed doors, she went to great lengths to present herself as the perfect society woman and hostess—a disconnect Foy strove to portray.

“She’s very proper and very put together. She’s not what you think the archetypal promiscuous woman is supposed to be like,” says Foy. “It’s quite difficult to try and translate that to a modern audience—that that was her interior life in a way.”

To prepare for the role, Foy pored over books about Campbell and listened to voice recordings the duchess made for a ghostwritten memoir.

“I got to hear her speak about experiences in her life, but…when you’re listening to the tapes, she’s not talking about all the things that people want to know about, which is who the man in the photograph was, who was she having affairs with,” Foy says. “She wants to talk about how she financed an animal refuge in the north of England.… She’s unknowable, really, because the stories about her seem to be at odds with how she comes across when you hear her interviewed or how she behaves.”

Foy was left to play armchair psychologist with the help of Phelps, hypothesizing why the duchess lived such a full romantic life. (In addition to a teen dalliance with actor David Niven, Campbell also counted Pakistani diplomat Aly Khan, millionaire aviator Glen Kidston, publishing heir Max Aitken, and Prince George, Duke of Kent, as suitors.)