Royals Prince William Angered Prince Harry by Involving Uncle Charles Spencer in Rift, New Book Claims Prince Harry "was furious with his elder brother for dragging other family members into the row," according to an excerpt from Battle of Brothers By Simon Perry Published on October 5, 2020 10:13 AM Share Tweet Pin Email Prince William angered his brother Prince Harry when he called upon their uncle Charles Spencer to intervene at the height of their rift. William, 38, was met by a “bitter explosion” from Harry, 36, after involving their late mother’s brother, according to a new biography. William believed Harry was moving too fast in the early days of his relationship with Meghan Markle and had asked his brother to take things more slowly. According to an excerpt from Battle of Brothers: William & Harry – The Inside Story of a Family in Tumult in the Daily Mail on Monday, veteran historian Robert Lacey writes that Harry reacted to the initial concern with “a brusque and offended pushback. Then, the older prince turned to his uncle Charles Spencer for help." Prince William and Prince Harry Issue Rare Joint Statement About Plans to Honor Mom Princess Diana Prince Harry and Prince William. Max Mumby/Indigo/Getty Images Charles Spencer. David Buchan/Getty “From time to time Diana's younger brother had played something of an honorary godfather to both boys in the years since the death of their mother, and their uncle agreed with William to see what he could do,” Lacey continues. “The result of the Spencer intervention was an even more bitter explosion. Once again Harry refused to slow down.” Harry “didn't blame his uncle. He understood why Diana's brother should want to help. Yet he was furious with his elder brother for dragging other family members into the row,” the excerpt says. And the “anger and mistrust - that distance - has lasted to the present day.” Lacey puts the request into perspective in his book, explaining how William had taken almost a decade to commit to wife Kate Middleton “for the sake of the monarchy. He had been auditioning her for a job all those years," he writes. While Harry “could not help but wonder whether Wills was really concerned about his personal happiness - or whether he was, once again and as per usual, thinking about the make-up and fortunes of 'the Firm' whose boss he would become one day?” Lacey continues. Prince William and Prince Harry in 2017. Eddie Mulholland/Getty Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! In excerpts published on Saturday, Lacey explored the months leading up to Harry and Meghan's departure from the royal family and the negotiations that took place at the so-called Sandringham summit. Prince William and Prince Harry's Deep Rift Explored in Revealing New Book Of the royal family summit in January, Lacey, who is also a historical consultant on Netflix’s The Crown, writes, "The Queen concluded that the four of them — Harry, William, Charles and herself — should sit down with their respective private secretaries at Sandringham the following Monday to hash things out, though William confided to a friend that he would much rather leave all the haggling to the staff. Battle of Brothers, which will be released Oct. 20 in the U.S. by Harper, is the second bombshell book to largely feature the brothers' split, following Finding Freedom, which was released in August. Prince William and Prince Harry. Shutterstock " 'I put my arm around my brother all our lives,' " William said, according to the new book, " 'and I can’t do it anymore. We’re separate entities.' " Lacey writes: "William maintained his distance for the Sandringham summit. 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."