Prince Harry was wrong to target his stepmother, Queen Camilla, because his father, King Charles, is very protective of her, according to a royal expert.

The Duke of Sussex has been estranged from his family after he and his wife, Meghan Markle, left the United Kingdom and moved to the United States. The ongoing family conflict was noticeable when Prince Harry said his father could not meet him when he traveled to England last month due to his "full program."

Royal biographer and commentator Christopher Andersen recently shared his thoughts on the royal father and son's relationship. He believes that Camilla was part of the equation as to why His Majesty was seemingly uninterested in meeting his youngest son.

"I think people have to realize that the one thing that Charles finds unforgivable is criticism of Camilla," Andersen told Fox News

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Prince Harry
Prince Harry, Duke of Sussex arrives for the Coronation of King Charles III and Queen Camilla at Westminster Abbey on May 6, 2023 in London, England.
(Photo : Andy Stenning - WPA Pool/Getty Images)

"There's no criticism of Camilla. And unfortunately for Harry... Harry said some pretty devastating things about her. He made it clear that he felt she was... the villain in the piece. I think that still bothers the King, and I don't know that it will be easy for him to [forgive]. I don't think they'll ever forgive Harry for that," the author of "The King" said before noting that Markle's husband is now "on his own."

Royal expert and commentator Richard Fitzwilliams seemingly shared the same sentiment regarding Camilla's significance in the monarch's life. According to him, Queen Camilla is a "non-negotiable" for Prince Harry's dad. King Charles even mentioned in his coronation invites last year that Camilla would also be crowned queen.

"Camilla was 'non-negotiable' for Charles and the photograph released by the Palace of them in the Blue Drawing Room of Buckingham Palace shows how happy they are together," Fitzwilliams told the Daily Mail in 2023 in the run-up to the King's coronation and months after Prince Harry released his controversial memoir.

"The King will have undoubtedly been outraged by Harry's recent attack on her in an interview to promote his memoir 'Spare,'" saying she was "dangerous" and citing "the need to rehabilitate her image."

Queen Elizabeth, King Charles and Camilla
TRH Prince Charles, the Prince of Wales, his wife Camilla, the Duchess Of Cornwall, and mother by HM Queen Elizabeth II, the Queen, leave the Service of Prayer and Dedication following their marriage at The Guildhall, at Windsor Castle on April 9, 2005 in Berkshire, England.
(Photo : ROTA-Pool/Getty Images)

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He added that the Sussexes were probably the ones who needed to rehabilitate their image because polls had shown their declining popularity.

A family friend previously told The Daily Beast in May that Prince Harry forced his dad to choose between him and his stepmother. However, while the King loves his sons, they couldn't compare to Camilla when it comes to winning his favor and affection.

Prince Harry
Prince Harry, Duke of Sussex looks on during day six of the Invictus Games Düsseldorf 2023 on September 15, 2023 in Duesseldorf, Germany.
(Photo : Lukas Schulze/Getty Images for Invictus Games Düsseldorf 2023)

"He has forced Charles to choose, which was a very silly thing to do because Camilla and he both chose each other a long time ago," the source said.

Meanwhile, royal expert and author Tom Quinn claimed that Prince Harry has seemingly taken Princess Diana's mantle and let "history repeat itself" by the way he attacked the royal family.

"Diana famously fell out with 'the firm' as she called it and spent much of her adult life criticizing an institution she felt had let her down. Harry has taken on his mother's mantle by carrying on exactly the same kind of criticism," Quinn said.

King Charles III And Queen Camilla Attend The UK D-Day80 National Commemorative Event In Normandy
VER-SUR-MER, FRANCE - JUNE 6: King Charles III and Queen Camilla attend the UK National Commemorative Event to mark the 80th Anniversary of the Normandy Landings on June 6, 2024 in Ver-Sur-Mer, France.
(Photo : Photo by Arthur Edwards - Pool/Getty Images)