Meghan Markle’s wedding to Prince Harry on Saturday will be a much smaller affair than when his brother Prince William wed Kate Middleton in 2011, but the overwhelming interest in the upcoming nuptials is causing a stir in the U.K. and making the royal family, who has been seen as stodgy or outdated at times, relevant, Princess Diana’s famed biographer Andrew Morton said.

Morton told Fox News there is a lot of interest surrounding the wedding of Markle and Harry because of the barriers Princess Diana’s youngest son is breaking by marrying Markle.

There’s as much excitement for this wedding as there was for William and Kate’s, Morton said, but in a different kind of way. "People are intrigued by her as an American actress, divorced, biracial [woman]. It’s the intrigue of it all,” he said.

Outside of Windsor Castle, media tents can be seen all along the stretch where Markle and Harry will travel by carriage. Camera crews crowd the sidewalks, with anchors reporting live in different languages about the upcoming festivities. In many souvenir shops on High Street, near the famed castle, reporters and photographers make the rounds alongside the royal enthusiasts who are there to buy wedding-themed merchandise.

“I have to say, I’ve not known the media as excited for a long time,” Morton mused. “I’m surprised by how big it is.”

He said the media frenzy is exactly what the royal family needs. Queen Elizabeth II, 92, has been the monarch for more than 65 years.

“It’s making the royal family relevant,” he explained. “It’s making it seem more inclusive. It’s making it seem more part of multiracial Britain. You walk through London and within 10 paces you see all races under the sun. It’s a very multiracial place. It’s a genuine melting pot so it is good to see the royal family embracing someone who is not white, [upper] class, typical people who the royal family married.”

Morton, who recently released a book titled “Meghan: A Hollywood Princess,” said Harry’s choice to marry Markle would make his mother proud. Morton got to know Princess Diana when he published “Diana: Her True Story” with the icon’s cooperation in 1992. The tell-all style biography was an instant best seller.

“I think she would be thrilled to see [Markle] is not the typical royal bride from the shire… She is someone challenging. [Diana] challenged an entire system and her legacy is that she changed the monarchy,” he said.

He’s sure Diana would have loved the “Suits” actress.

“He’s got a spring in his step,” Morton said of Harry. “He’s whistling a merry tune. He looks like a man who has won the lottery… and she would be thrilled as a parent to see him so happy.”

Morton praised Markle for how she’s helped the prince’s image.

“I think wild child Harry is now saint Harry. He is now focused on the Commonwealth, on representing the hundreds of millions of youth of the commonwealth. He’s settling down. He wants to be a dad. The word from the palace is that he is besotted.”

But not everyone has been fully accepting of the 36-year-old royal-to-be.

“I’ve heard some racist comments, some pejorative comments,” he said. “Most people are very favorable to her but some people are quite hostile. There is a cohort of people who are very supportive of everything that Meghan does, and there are some people that are very skeptical of her. She has only just joined the family and people are only just starting to get to know her. There’s a lot of learning that has to be done on both sides.

“For the British she’s been around for what? A year and a half. Most people did not watch ‘Suits.’ In Britain, that was on an obscure channel and so she is sort of having to introduce herself,” he noted.

Morton said one thing he’s noticed is that there is a lot of chatter surrounding whether or not Markle’s marriage to the prince will last.

“You never got that with William and Catherine,” he pointed out. “I think the fact that she has been divorced has given people license to say that.”

Morton, for one, feels very confident in the union. He said the starlet is fitting into her role as a full-time royal already.

“She’s already a natural,” he raved. “Just compare it to when Diana and Kate ‒ and for that matter Fergie ‒ first entered that arena. Diana did not do an engagement until three months after the wedding… [and] not very many before. And Catherine, her first engagement was not [until two months before the wedding]... Look at Meghan, she’s accompanied the queen to a service... She’s being thrown in at the deep end… and she is swimming, and that is what she wanted, by the way.

“She made it perfectly clear. Her mantra is ‘I don’t want to be a lady that lunches. I want to be a lady that works.’”