Author Omid Scobie writes in his new book ‘Endgame’ that “Diana cosplay has become a royal staple”

Meghan Markle, Princess Diana and Kate Middleton. Photo: Pool/Samir Hussein/WireImage;  David Levenson/Getty Images; Samir Hussein/Samir Hussein/WireImage

Meghan Markle and Kate Middleton’s style tributes to their late mother-in-law Princess Diana are no coincidence, according to a new book.

Omid Scobie writes in his new book Endgame that the palace “shamelessly leverages” Princess Diana’s lasting popularity, including encouraging Prince Harry and Prince William’s wives to replicate her fashion in an attempt for “some of Diana’s shine to rub off on them.” In addition to sporting looks reminiscent of Diana’s past ensembles, both Meghan and Kate regularly wear pieces of jewelry from their mother-in-law’s collection.

“Diana cosplay has become a royal staple,” Scobie says in the book, out now.

The author adds that a source told him that these decisions are “always discussed” with Prince William and Prince Harry.

Scobie writes while Meghan and Kate’s tributes to Diana could be a “sweet gesture,” he also called it “slightly queasy” as the move is “orchestrated” by the palace — which he says contributed to Diana’s “living misery.”

Kate Middleton and Princess Diana in polka dots. Chris Jackson/Getty; Tim Graham Photo Library via Getty
Every Time Meghan Markle and Kate Middleton Have Worn Princess Diana’s Jewelry

Princess Kate, 41, regularly wears outfits that remind royal watchers of Princess Diana’s style.

“I think we have seen lots of examples where the reference is very intentional and I think that Kate uses fashion to pay tribute to Diana in a very positive way,” Bethan Holt, Fashion News and Features Director of The Daily Telegraph, previously told PEOPLE.

From timeless patterns like polka dots to a houndstooth coat dress, the new Princess of Wales is making these classic looks her own.

“What’s really key about these times when Kate references Diana, it’s not like a costume. She brings it right up to date so she makes it look relevant for now,” Holt, the author of The Queen: 70 Years of Majestic Style, said. “She’s not doing an ’80s power shoulder or a puffball skirt, she’s making it look sleeker and more contemporary. She makes it her own without looking like she’s playing ‘dress up as Diana.’ “

Kate Middleton and Princess Diana.David Fisher/REX/Shutterstock; Bettmann/Getty

One of Kate’s most memorable nods to Princess Diana was in 2018 when Kate and William introduced their third child, Prince Louis, to the world outside the hospital. The new mom of three wore a red dress with a white Peter Pan collar — 34 years after Princess Diana presented Prince Harry to the public in a similar look.

Princess Kate also has a number of jewelry pieces from Princess Diana’s collection, including a piece she wears constantly: their shared sapphire and diamond engagement ring.

During their official post-engagement interview, where Kate wore a royal blue dress by Issa that perfectly matched the ring, Prince William explained why the piece was so special to him.

“It’s my mother’s engagement ring so, I thought it was quite nice because obviously, she’s not going to be around to share any of the fun and excitement of it all — this was my way of keeping her sort of close to it all,” he said.

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Meghan Markle and Princess Diana. Chris Jackson – WPA Pool/Getty;

During her time as a working member of the royal family, Meghan was also known for her style tributes to Diana. The first major moment came on her wedding day to Prince Harry in 2018, when her outfit changed for the evening reception included an aquamarine ring with special meaning to her mother-in-law. The accessory was a gift for Diana to wear in place of her engagement ring after her divorce from then-Prince Charles in 1996.

The Duchess of Sussex’s decision to often lean toward pants and menswear during public outings is a nod to Diana, who loved both styles and wore them often.

During her pregnancy with Prince Archie, Meghan also followed Diana’s maternity style cues, including a bold and unusual red and purple combination.

Meghan Markle and Princess Diana. Pool/Samir Hussein/WireImage; Tim Graham/Getty

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Recently speaking to PEOPLE about Endgame, Scobie said that Meghan has “moved on” from the royals, but things are different for Harry.

“Quite early on in the [book-writing] process, some of those Meghan sources that I really leant on in the earlier years this time were like, ‘You know what? She doesn’t want anything to do with it,’ ” says the author, who has covered the royal family for more than a decade.

“For Harry it’s different. He still has unfinished business when it comes to his battles with the press. His challenge will be to find something that balances that out so we can see him working in a space that isn’t connected to the ties that bind from the past,” Scobie adds.