Battle of the Brothers, written by royal biographer and historian Robert Lacey, documents the breakdown of Prince Harry and Prince William’s relationship. It reveals the Royal Family’s frustration about Prince Harry and Meghan Markle’s decision to step down as senior royals earlier this year.
Mr Lacey said Prince William was infuriated by his brother’s behaviour and refused to meet with him and the Queen for lunch before the “Sandringham Summit”.
Her Majesty thought the Sussexes were “erratic and impulsive” with their decisions, according Mr Lacey.
Mr Lacey has written biographies of the Queen and is known for consulting Netflix’s royal TV show The Crown.
The historian spoke to royal insiders to write his new book that comes after the publication of Finding Freedom – an explosive book about the Sussex’ royal exit released earlier this year.
Mr Lacey wrote in the Daily Mail about how Prince William was “so angry” with his brother’s behaviour when he decided to step down as a senior member of the Royal Family.
He said: “It was a pity that William was now so angry that he was not speaking to him anymore. It was as if Harry had become un-brothered.
“The harsh reality was that the gospel according to Meghan — as evidenced in the special issue of Vogue she had edited — was simply not royal, nor was it in harmony with mainstream, ‘un-woke’ British opinion.
“William and all the senior members of the royal family — not least Prince Charles and the Queen — had come to feel the same.”
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“The Queen had suggested the family should gather for lunch before their big pow-wow in the library that afternoon, but he refused his grandmother’s invitation.
“He would obviously turn up at 2pm for the meeting, he said, but he only wanted to talk business.
“The Prince himself has not confirmed his friends’ speculation that he was so furious with his younger brother that he would not be able to endure the hypocrisy of smiling at him over lunch.”
In January, the Duke and Duchess of Sussex announced their plans to step down as senior members of the Royal Family on their now defunct Instagram account.
It came after the couple confessed during an interview with ITV journalist, Tom Brady, that they were struggling.
After their announcement to step down, the couple originally planned to split their time between the UK and North America.
But the Sussexes have been living in the US since March with their baby son Archie.
The Duke and Duchess recently announced that they have signed a production deal with online streaming giant Netflix.
They said they wanted to focus on creating content “that informs but also gives hope”.
Soon after announcing the deal, the couple revealed that they planned to fully reimburse the £2.4million used to renovate their UK home, Frogmore Cottage.