Duke and Duchess of Sussex 'discussed leaving the kingdom before they got married' because Duke was 'deeply dissatisfied for a long time', claims a new book.

Prince Harry, 35, and Meghan Markle, 38, currently live in Tyler Perry's $ 18 million mansion after retiring from the royal post in March.

Sources have revealed that the biography 'Finding Freedom' will be published online on August 11 and will 'explore the couple's journey' to their decision.

An insider told The Sun: "The seeds of Megx (departure from the kingdom) were sown before they were married. The truth is that Harry has been deeply dissatisfied for a long time. "

The source continued: "He and Meghan discussed openly before they got married."

They added that the biography would "make it clear" that the choice to leave life as kings was "far from a premature decision."

Co-author Omid Scobie, who has accompanied Prince Harry and Meghan Markle on many royal tours, recently told The Heir Pod podcast that the story has taken turns that 'even Sussexes didn't expect'.

He said: 'This project started about two years ago and there have been twists and turns that no one expected. This is something no one expected.

"I don't even think Harry and Meghan, who on their behalf fought with the reality of the situation, expected things to turn out the way they did."

Explaining that the biography gives a true version of their story, he said: 'I've been in so many engagements and about them as much as possible, and I've talked to so many people in their lives, so that no stone has been left untouched. "

The book's description says that 'few people know the true story of Harry and Meghan'.

He promises to go beyond the headlines to reveal unknown details of the lives of Harry and Meghan, dismissing numerous rumors and misunderstandings about the couple.

The 320-page biography, which will be released in August, is expected to be a global bestseller.