Inside the Glamorous Life of Britain’s First Black Marchioness

Dec. 23, 2013— -- Emma McQuiston is about to make history, and it's not because of her fairytale castle wedding this past June to Ceawlin Thynn, Viscount Weymouth, which included 355 guests, a staff of almost 200 and a magician.

The British bombshell is set to become Britain's first black marchioness, which is just one step below a duchess. McQuiston currently holds the title of Viscountess Weymouth.

"It's been a positive thing just to show that, you know, hopefully race doesn't need to determine who you are, what you're like or where you need to be," McQuiston, 27, told ABC News' "20/20" in her first American television interview. "Of course it should be irrelevant."

Though technically a commoner, McQuiston had far from humble beginnings. Coming from wealth, her mother is a British socialite, and her father is an Oxford University-educated Nigerian oil tycoon.

Thynn's father is Alexander, the infamous Marquess of Bath, known for his long hair, flamboyant clothing, and the images of naked woman he painted over the walls of his estate, named Longleat, where McQuiston and Thynn now live. When Alexander passes away, Thynn and McQuiston will assume the titles of Marquess and Marchioness of Bath.

It was at another family wedding that the two first met as children. She was just three years old.

"In my mind, Emma was always a child, or a teenager, you know," Thynn, 39, told 20/20. "We re-met and Emmy was now an adult and a new dynamic ensued."

"I already knew him and the family, but I never dreamed this would happen," McQuiston said. "I think I wouldn't even let myself hope before that this would happen because it's just so surreal. Still, [it] is quite surreal now."

When McQuiston married Thynn, she not only married a aristocrat, but she also married into a business.

Longleat has a safari park and a couple of restaurants and was the first stately home in England to open to the public in order to pay its taxes. The estate is also a venue for conferences and weddings. While living at Longleat, McQuiston represents the estate and becomes a part of its history.

"I'm having my portrait painted, for example, so that will be then put up at Longleat and hopefully stay here for a long time," McQuiston explained. "You become part of a long line that goes back and will hopefully continue. That's what you want. You just want the house to survive, and you do everything you can to maintain it, look after it and support it ... to sort of protect it."

In spite of her wealth, the 27-year-old actually has career plans of her own. Interested in fashion, McQuiston posed for the cover of "You" magazine just a couple of months ago. She also has ambitions of having her own cooking show and has her own food blog.

"My mum originally taught me to cook...growing up I just became, you know, more curious about nutrition and, you know, food from across the seas," McQuiston explained.

Even with her fortunate upbringing, McQuiston still feels lucky to be living at Longleat.

"Just, you never take it for granted. You [can] never not be appreciative...of being so fortunate," McQuiston said.

"I didn't predict this would happen at all. I could never have dreamt or hoped for this or let myself."