Last month, Emma, Duchess of Rutland sat in her drawing room and weighed the pros and cons of living over the shop. Specifically, Belvoir Castle, a stately and splendid pile perched on a wooded hilltop in the English countryside with more than 356 rooms and soaring neo-Gothic towers and turrets. It has been the site of the family seat since the 16th century.

“Well, it is magnificent, of course, and we are incredibly lucky, but you never quite know who is in here with you,” she said. “There isn’t privacy in the way most people might expect from their homes. And don’t get me started on the ghosts.”

A private secretary wandered by with a giant flag that needed repair before it could fly from the castle’s two-and-a-half-acre roof. Downstairs, the castle tearoom hummed with tables of tourists sampling scones with jams from the Belvoir estate. Nearby, a platoon of pickup trucks bounced across a field packing up obstacles from a recent Tough Mudder endurance event. For the duchess, born Emma Watkins, it was a day like any other.

A farmer’s daughter from the Welsh borders, she moved to Belvoir in 2001 when her husband became the 11th Duke of Rutland, one of the most senior hereditary titles in England. He may have inherited a fairy-tale castle, but they were also landed with 12 million pounds (almost $15.5 million) of inheritance taxes and, in her words, “battalions of rats and staff who clearly preferred the former incumbents to us.”

In the years since, as both chatelaine and chief executive, the duchess has brokered filming and event deals, streamlined the operations of the estate and undertaken a costly restoration to safeguard Belvoir for the next generation.

Recently, despite tabloid scrutiny for her unconventional living arrangements (the duke and duchess are legally separated and have lived in different wings since 2012) and the fact that Britain’s historic houses are increasingly part of a brewing culture war over how the country should reckon with its colonial past, the duchess has displayed a growing taste for the limelight, albeit on her terms.

In 2020, she started a podcast, “Duchess,” in which she interviews other duchesses. A Duchess Gallery shop on the estate sells branded clothing, home wares, gins, wines and cider. And last year the duchess published “The Accidental Duchess,” an autobiography that includes candid accounts of her husband’s serial affairs and her string of miscarriages while raising five children.

Now 59, she is emerging as one of the more amiable public faces of Britain’s aristocracy at a time when many prefer to remain below the radar. That means she is more sanguine than most about airing dirty laundry.

Brisk but friendly, she crossed her bare, toned legs (she said she runs about two miles each day after a cup of Earl Grey tea at sunrise) as she recalled an early morning attempt to put a load of clothes into the washing machine. Her utility room, she said, is on the other side of a landing from her living quarters, which are concealed from the public by screens. She wore what she described as “a granny nightie” as she nipped across the hall.

“To my horror, there were 20 or 30 mesmerized Texans from a coach tour all pointing at me from a staircase,” she said. She smiled and stroked the duke’s little Shih Tzu, Spitfire, who was resting in her lap with a resigned air.

“There is always something happening here,” she said. “We do what we need to do to keep the lights on.”

It is an idiosyncratic — and fiercely protected — quirk of the British cultural landscape that so many of its stately homes can have visitors even while the families that own them remain in residence. About one-third of the historic houses are in the care of conservation charities like the National Trust or English Heritage, but Belvoir Castle, in Leicestershire, remains in private hands.

“Many houses opened up for the first time after the Second World War, when new income streams needed to be found to meet repair bills and when houses were being knocked down because owners could no longer manage to keep them,” said Ben Cowell, the director general of Historic Houses, a nonprofit that helps preserve about 1,500 privately owned properties.

Starting in the 1970s, changing laws about inheritance taxes made it fiscally advantageous to open up houses to the public for a certain number of days each year, generating funds for eye-watering preservation costs. (Today, Historic Houses estimates its properties have, collectively, a roughly £2 billion (about $2.5 billion) repair and maintenance backlog.)

“We find that visitors really love seeing houses that remain lived-in homes, as opposed to being museum pieces where nobody now lives,” Mr. Cowell said.

At Belvoir, some even stay the night. The castle, which was a stand-in for Windsor Castle in “The Crown” and has been featured in movies including “The Da Vinci Code” and “The Young Victoria,” often hosts guests for weekend events and photo shoots. They can stay in sumptuous state bedrooms, several of which are newly renovated, including one that, in collaboration with de Gournay, is covered in hand-painted wallpapers. (Belvoir wallpapers are, naturally, available to order.)

In fact, wallpaper preservation is often a priority for the duchess, a onetime interior decorator (and real estate agent and opera singer). It is a cornerstone of her new charitable initiative, American Friends of Belvoir Castle, which will host an inaugural fund-raising gala at the Breakers in Palm Beach, Fla., next year.

An American reverence for Britain’s grand houses, spurred by the popularity of shows like “The Crown” and “Downton Abbey,” has been important for the castle coffers. After all, Belvoir — pronounced “beaver” — costs about £1 million a year to run “just standing still,” the duchess said. She is always looking for donors.

“ Americans love to trace their roots and the sense of history we have here,” she said. “It has been simply wonderful to have so many listeners from there for ‘Duchess.’”

Ah yes, the “Duchess” podcast. Meghan Markle is not the only duchess in the podcast game. (A biography of the Duchess of Sussex sat on an ottoman in the family drawing room at Belvoir.)

But why would the Duchess of Rutland, who said she didn’t even know what a podcast was until the idea was presented to her, agree to interview other women who run stately homes, including Lady Henrietta Spencer Churchill of Blenheim Palace and the Duchess of Argyll of Inveraray Castle and Countess Spencer of Althorp House? Was she not worried that a project with such an unashamedly niche and elitist focus could backfire? The duchess looked shocked at the suggestion.

“Not for a moment,” she said. “People can like me or hate me. but I have never been one to dwell on others’ negativity. ‘Duchess’ was about giving people a glimpse behind the scenes of what it’s like to be a woman running one of these properties. And the fact that it can be jolly hard work. I don’t think I’ve had breakfast in bed once in the two decades I’ve lived here.”

The podcast was the brainchild of the duchess’s oldest daughter, Lady Violet Manners, who came up with the idea while studying at U.C.L.A. Violet, her mother said, felt sure there was an audience for such a series. The duchess, who is an adept interviewer, cast herself in the mold of “upmarket showgirl,” she said, happy to come on and do her bit.

Lady Violet found inspiration for the podcast from years of listening to after-dinner conversation between duchesses as they sat by the Belvoir fire, swapping recommendations for curtain makers and stonemasons or tips on what to do when a flood happens or a ceiling caves in. What struck the duchess when recording the podcasts was that many of the women, or “girls,” as she called them, were of a similar mind-set. Namely, that they were custodians of personal and collective monuments to important national history and were largely unafraid to get their hands dirty.

“I also realized that the British aristocracy have been rather practical at picking the right sort of wife they needed at a particular time, which is partly why they’ve kept going for generations,” the duchess said. Sorts like an artistic visionary or an American heiress. Or someone like her.

“I was raised on a farm,” she said. “I didn’t come with a title or know a thing about the worlds of heritage or class, but I will do everything I possibly can for Belvoir to thrive for as long as I’m here.”

Some of these efforts have gone above and beyond what many would be prepared to do. In her autobiography, the duchess describes weeping while breastfeeding her son Charles, the Belvoir heir, the first time she realized the duke had been unfaithful — at his 1920s-themed 50th birthday party in 2009. It was a moment, she wrote, that left her “feeling as if I’d been punched and fighting for breath.”

She locked herself in the state dining room to smoke cigarettes, drink wine and dance (alone) to “I Will Survive.” A divorce lawyer told her she could expect to walk away with £30 million, she said. But she chose to stay, the duke residing in the Shepherds’ Tower and the duchess in the Nursery Wing.

“It’s a very modern arrangement, yet very French 18th century at the same time,” Nicky Haslam, the interior designer and socialite, said in an article in Vanity Fair. The duke, a vocal fan of Donald Trump and Brexit who has written several books on subjects like naval history, has lived at the castle with various partners in the years since the separation. For the last decade, the duchess has been in a relationship with Phil Burtt, the estate manager.

“It’s not without its complications, but when is anything perfect?” said the duchess, who said she had a breakdown in 2017 when she walked across the castle to her late mother-in-law’s bedroom and didn’t emerge for months. She stressed that she was “much better” now and that crystals, reiki and meditation had all helped. And, she said, she and the duke were “on the same page,” with a friendship and a deal in place that will allow her to remain at Belvoir as chief executive until she is 65. They even share the occasional supper together.

“Money is not my God,” she said. “How awful it would be to go down in history as the person who caused this place to be broken up after hundreds of years.”

The duchess still believes in primogeniture, or the right of succession belonging to the firstborn son, and doesn’t think that her other four children would want the burden of such an inheritance anyway. Lady Violet, Lady Alice and Lady Eliza, once known as the beautiful “bad-Manners sisters” on account of London parties so raucous that their neighbors complained to the newspapers, are now working in creative consultancy, styling and interior design, while Charles works in the City of London and his brother Hugo attends Newcastle University.

And while she has loved working on the podcast, the duchess said, she is now handing over the reins to Lady Violet for the next series, which begins Aug. 17 and features custodians of historic houses presenting individual episodes themselves. The duchess wants to focus on the estate’s commercial enterprises, including a retail village and farm, as well as a new YouTube series that delves into the history of Belvoir, rather than houses elsewhere.

Perhaps building a multiplatform social media following was part and parcel with being a successful 21st-century duchess?

“Oh no, no, I don’t think so,” the duchess said. “Most of the girls I interviewed probably think ‘Oh no, what on earth is she doing now?’ Putting yourself out there and talking about money can still be seen by much of the British aristocracy with an eye roll. But I just do the work and keep going. I know why I do what I do.”