• Prince Harry always felt like a spare growing up, according to the book "Finding Freedom"
  • The Duke of Sussex had always wanted to break free from Prince William and Kate Middleton
  • Royal expert Katie Nicholl said Markle was Prince Harry's catalyst in breaking free from the Cambridges

Meghan Markle  played an important role in helping Prince Harry achieve what he had always wanted — to break free from his brother Prince William and sister-in-law Kate Middleton, according to royal expert Katie Nicholl.

Nicholl, who is the author of several royal biographies including "William and Harry," "Kate," and "Harry and Meghan," spoke with Entertainment Tonight about Omid Scobie and Carolyn Durand's new book "Finding Freedom." During the interview, she talked about how Prince Harry had always wanted to be on his own despite Prince William and Kate Middleton's effort to make him feel that he was part of the team, and how Markle pushed him to break free from the Cambridges.

"I think Meghan has very much been the catalyst in giving him that confidence to break free from William and Kate, and to break free from that trio dynamic, which was at times cozy and convenient, but actually wasn't really what he wanted," Nicholl said.

According to the royal expert, the book highlighted how Prince Harry lived his life as a spare when he was with his brother, the future king.

"One of the themes that seems to be recurrent in ‘Finding Freedom’ is that Harry felt very much like a spare wheel," Nicholl said.

"While the media loved this idea of a royal threesome (Kate Middleton, Prince William and Prince Harry), for Harry, he very much felt like a spare wheel. At points [in time], I even heard him complaining that he felt like the gooseberry, the third one along at the date. He never quite fitted in."

Nicholl recognized the Duke and Duchess of Cambridge's effort in trying to make Prince Harry feel that they were a team and he was a significant part of the royal trio. However, Prince William's brother had always wanted to be "his own person" and Markle's arrival in his life boosted his confidence and enabled him to break free from his brother and sister-in-law's shadow.

Nicholl was also convinced that Prince Harry and Markle's decision to move to Los Angeles wasn't only the duchess' idea. Nicholl explained that unknown to many, "Harry is a pretty opinionated and strong-willed man."

"She gave him a new confidence, but I think the truth is that, for a long while, Prince Harry has wanted out," Nicholl added.

"This was a prince who'd spoken quite vocally about the restrictions of being a royal, the weight of burden, a boy who said he wish he hadn't at times been born a prince. I think that says a lot about Prince Harry."

Britain's Prince Harry and Meghan Markle Britain's Prince Harry and Meghan Markle are bowing out entirely from representing the monarchy. Photo: AFP/Daniel LEAL-OLIVAS