Prince Harry complained of feeling like a third wheel on official engagements with William and Kate, a royal expert says.
Harry, 35, currently living in LA with wife Meghan, 38, and their young son Archie, would often go to events with his brother and sister-in-law before having a family of his own, writes the Daily Mail.
Royal expert Katie Nicholl told ET Canada that Harry feeling like a third wheel was a "recurring theme" in the new biography Finding Freedom.
She said that while the media loved the thought of Harry, William and Kate being a great team, Harry often 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," she said.
Nicholl, the royal editor for Vanity Fair, said the Duke and Duchess of Cambridge made an effort to help Harry to feel "part of the team", but that Harry "always wanted to be his own person".
"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 cosy and convenient, but actually wasn't really what he wanted."
She added that Meghan was "a driving force" for Harry and that "people don't give her enough credit" for helping his confidence.
Authors of the biography say they spoke to over 100 sources for the book, including close friends of Harry and Meghan and royal aides.
Harry and Meghan deny they had anything to do with the book despite the intimate nature of some of its details.
The biography claims Harry and Meghan "hurt" the Queen by planning out their royal roles without her approval.
And the Queen was reportedly "blindsided" when they launched their Sussex Royal website alongside their Megxit announcement in January.