“Outrageous” is introducing the Mitford sisters to new audiences, almost a century after they first made their mark on British society as young adults.

Bessie Carter leads the series as Nancy Mitford, the oldest of the six Mitford sisters and the show’s narrator. The family was embedded in the fabric of London’s aristocratic society in the 1930s and beyond, and part of what became known as the “Bright Young Things,” a group that was young, rich, arty and prone to party.

 ”The first episode is very much setting up the chaotic time that we are in, and these young sisters who were chaotic, young, hungry, passionate, teenagers into their early 20s,” says Carter. “The backdrop of that 1930s storm-brewing-energy, the cracks within the family, and the betrayals that start to take place — [the show] tracks it really well.”

“Outrageous” is based on Mary Lovell’s biographic book “The Mitford Girls,” which Carter read in anticipation of working on the series. “Finding out this one family, just how infamous and scandalous they all became, was really incredible,” says the actress. “Sometimes fact is stranger than fiction, and it very much felt like that.”

Several of the six sisters veered controversial: Diana, whose first husband was Bryan Guinness, later married the fascist leader of Britain and was imprisoned during WWII for her support of Nazi Germany, views shared by her sister Unity — and criticized by novelist sister Nancy. Other sisters were communist Jessica, Pamela, and Deborah, who became Duchess of Devonshire.

“I think anyone who has siblings [will be familiar with the idea], you are all raised under one roof and when one sibling goes one way, you’re probably quite likely to want to vehemently go the other way,” says Carter. “I loved that this [show] was gonna look at that and explore why these girls effectively went in such opposing directions in their lives — in sort of every possible direction.”

Carter discovered several personal connections to her character coming into the project, stretching back to birth: Although the experiences were decades apart, Nancy worked at the same hospital where Carter was born; both attended the same school as kids; and Carter grew up 10 minutes from where Mitford had lived as an adult.

The 31-year-old actress first became very familiar with Mitford’s voice through narrating her novel “The Pursuit of Love” five years ago for Audible, “one of the most compelling audiobooks I’ve ever done,” she says. Carter credits “Outrageous” screenwriter Sarah Williams’ choice to make Nancy the narrator within the TV series, rooting the story in Nancy’s “witty, tongue-in-cheek, incredibly intelligent tone.” “I thought that was such a clever element that she made the storyteller in the family — the author — the storyteller of the series.”

Carter describes the series as a “different type of period drama,” one with a “youthful, fresh, energetic, quite punky angle,” she says. “It’s got an energy to it, which I think will compel the modern audience to keep tuning in each week.” But while the tone veers contemporary, the costume is rooted in the period, and Carter credits wardrobe with helping her to develop authentic connection with her characters. In “Outrageous,” the various settings the sisters find themselves in have distinct sartorial worlds.

“We had the countryside world, which was a bit more sort of wool and leather, going riding. And then you had the London scene, which was bohemian,” she says. “A bit more slinky and maybe a shoulder was revealed and there was a bit of eye shadow. It’s very true to how we live: we dress differently depending on where we are. If you’re going home, if you’re going for a walk in the country, if you’re going out to the pub with your mates, you wear different things,” she adds. “I loved stepping into the authenticity of that. It did half of my work for me, and I’m not joking.”

Carter is the daughter of “Downton Abbey” actor Jim Carter and actress Dame Imelda Staunton. Although acting as a profession was normalized early on, she can’t pinpoint the exact moment she decided to follow in their footsteps, but knew it was the only path she was interested in taking.

“I just loved being in a group of people who wanted to play and dress up and be silly and tell a story,” she says. She immersed herself in theater as a teenager, and after completing her A levels took a break to backpack in Australia before returning to London to work as an assistant stage manager at a pub theater and dresser for “Mama Mia” in the West End. From there, she was accepted to the drama program at the Guildhall School. Since graduating in 2016, Carter has notably portrayed the red-haired and audacious Prudence Featherington in all three seasons of “Bridgerton” for Netflix. 

Ahead of the premiere of “Outrageous” at the Tribeca Festival and wider BritBox release in mid-June, Carter starred in a West End production of “Mrs. Warren’s Profession” opposite her mother. The actresses brought their relationship to the stage, portraying the central mother-and-daughter duo in the George Bernard Shaw play. The production was controversial when it was first performed in the early 1900s; the titular character is a former prostitute and brothel operator.

“My mom read it and then she texted me and she was like, you should read this play,” says Carter. “I’ve never worked with her before. There’s actually a line in the play by one of the other characters, which is, ‘well, they don’t even look like mother and daughter,’ which I think is perfect,” adds Carter, who stands nearly a foot taller than her mother. “You really wouldn’t pick us out of a crowd. We’re not even meant to look like each other [in the play], and it’s just a phenomenal piece of writing.”

For Carter, the dream is to continuing going back and forth between screen projects and the stage.

“With TV and film, there is a focus that you need,” she says. “You’re up at 5 in the morning and you might be doing the same scene from 8 o’clock in the morning till 7 p.m. at night, and you need to be able to deliver the same amount of emotional intensity. Some of the scenes in ‘Bridgerton’ went on for about five days; those ball scenes,” she adds. “So that’s a different type of skill and that’s a really nice challenge. But with theater, there’s something about being in a rehearsal room for six weeks with a company where you are all deciding how to tell the story together. And then you get it up on its feet and then you just have to do it live again and again and again.”