The Duke and Duchess of Sussex "stepped back" from the Royal Family in 2020, now living in California.
Their brief spell as a working royal couple was tumultuous, not least after their 16-day tour of Australia.
The Sussexes toured Australia, New Zealand, Tonga and Fiji to huge fanfare in 2018, with the highlight arguably being their visit to Invictus Games in Sydney.
Journalist Tom Bower has documented the tour in his new book 'Revenge: Meghan, Harry and the war with the Windsors'.
Meghan Markle and Prince Harry
PA
Princess Diana
John Stillwell
In it, he says Meghan and Harry felt they had the qualities to modernise the monarchy and take after the late Princess Diana.
He writes: "The Sussexes had convinced themselves that their Australian success blessed them with Diana’s magic.
"Meghan could not understand that Diana had won the public's affection after years of work.
"Neither she nor Harry could grasp that emulating Diana required time, to weave a narrative and create a brand from which influence would flow."
Mr Bower also writes about how Meghan was asked to appear on the cover of Vanity Fair's September 2017 issue.
The magazine ran with the headline 'Wild About Harry' on its front page – choosing to focus on the former Suits star's relationship with the prince, rather than her charity work.
When pre-publication copies were sent to the Palace, Meghan is said to have reacted "hysterically" as she "furiously" phoned her PR firm.
In the 2017 culture magazine, Meghan said: "I'm sure there will be a time when we will have to come forward and present ourselves and have stories to tell, but I hope what people will understand is that this is our time.
"This is for us. It's part of what makes it so special, that it's just ours. But we're happy.
"Personally, I love a great love story."
Mr Bower reports that Meghan was livid when Vanity Fair chose to lead their feature on these quotes, rather than focus on their philanthropy.