Prince Harry and Meghan Markle's young son Archie gave them the "energy to stand up for what was right", the author of an unauthorised biography has claimed.
The couple controversially stepped down as senior royals last year and moved from the UK to carve out a new life in California.
Since then they've bought an £11million mansion, signed multi-million dollar deals with the likes of Netflix and Spotify and welcomed their second child Lilibet.
Now, Omid Scobie, one of the authors behind the biography Finding Freedom, has said the couple were "afraid of the consequences" of stepping back from the Firm.
But explained it was the birth of Archie in 2019 that spurred on their decision.
In an interview with PEOPLE magazine, he said: "They were quite afraid of the consequences of stepping away and challenging the system."
When the couple welcomed Archie, Omid added: "That's what gave them the energy to stand up for what was right for them, regardless of what the consequences were.
"As we have seen, those consequences have been pretty major."
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Omid's interview comes as he and fellow writer Carolyn Durand prepare to release the paperback version of Finding Freedom that includes a new epilogue.
The release on August 31 coincides with the anniversary of Princess Diana's death.
An extract from the updated book has also been published in this week's PEOPLE magazine.
In the extract, sources say that despite the difficulties they've faced, Harry and Meghan have "no regrets" about leaving the royal family.
It also sees friends of the couple claim the Queen has not taken "full ownership" of the issues they raised during their bombshell interview with Oprah Winfrey.
Among them was that Meghan was denied help for her mental health during her time in the Firm and that a member of the family asked questions about Archie's skin colour.
Following the airing of the chat, Buckingham Palace issued a statement saying the Queen was "saddened" by the allegations, but added that "some recollections may vary".
In a new extract from the book, the authors say the statement "did not go unnoticed".
The extract also claims that Harry booked a one-way ticket to the UK for Prince Philip's funeral in the hope he could come together and talk with his family amid a rift with his brother Prince William and dad Prince Charles.
Finding Freedom, originally published last year, chronicles Harry and Meghan's romance and brief period as members of the monarchy before they broke away to forge a new life for themselves in the US.
The updated book is said to have been written with the participation of those closest to the Sussexes.
Last month, publisher of the book HarperCollins said the epilogue in the paperback edition will share : "Behind the scenes of Harry and Meghan's groundbreaking interview with Oprah, details behind the couple's move to California (and) the various philanthropic and business endeavours the Sussexes have been involved with since their move and what's to come with Archewell Productions."
It will also feature: "The continuous challenges the couple face regarding privacy and the British press (and) the heartbreak the couple felt over Prince Philip's death."
