An investigative journalist has claimed the Sussexes "convinced themselves" Prince William was "jealous" of their success" after their first royal tour as a married couple in Oceania.
Prince Harry and Meghan Markle undertook an incredible 75 engagements across 16 days during the tour, which saw them visit Australia, New Zealand, Fiji and Tonga.
The Duke and Duchess of Sussex were constantly welcomed by huge crowds as they travelled around.
In his upcoming book 'Meghan, Harry and the war between the Windsors', investigative journalist Tom Bower reports Meghan and Harry "convinced themselves" that the Duke of Cambridge felt "jealous" of the success of their tour, reports the Express.
In an extract of the book published by the Sunday Times Bower wrote: "On October 23, one week into the tour, the die was cast.
"Harry and Meghan seemed to have convinced themselves that William was jealous of their success in Australia.
"The time was right for 'change'. They needed to break out of Kensington Palace’s claustrophobic fishbowl.
"Harry proposed that the Palace should rewrite the rulebook.
"Rather than Meghan being a dutiful member of the supporting cast she should star as a campaigner, independent of the Cambridges and even of the Queen."
The author also claimed that, "perhaps encouraged by Harry, Meghan appeared to conjure a fantasy that she could provide the leadership the monarchy required".
The couple actually referred to the tour themselves during their bombshell interview with Oprah Winfrey last March.
When Oprah asked Harry if he thought Meghan had been received well by his family at the start, he replied: "Yes. Far better than I expected".
In his book, Bower also claims Meghan and Harry had a "tense" conference call with the Queen and Prince Charles.
In 2018, the Duchess of Sussex was allegedly urged by Charles and his mother to reconcile with her estranged father after he made a number of embarrassing TV interview appearances.
Charles and Camilla, Duchess of Cornwall, were at the Castle of Mey, former home of the Queen Mother, in July when the call took place, according to biographer Tom Bower.
It's been reported Charles "berated" Harry over his wife's decision not to visit Thomas Markle and repair the broken relationship.
Representatives for the Sussexes have been approached for comment.