The Gist

• Kate Middleton once “saw it as her duty” to keep brothers Prince William and Prince Harry “on the same team,” according to a new royal biography.

• Russell Myers’s William and Catherine: The Monarchy’s New Era: The Inside Story came out in the U.S. on March 10.

• In the book, Myers wrote that Kate had long seen the brothers’ “competitive nature” and “often acted as a peacemaker” between them.

Kate Middleton has been in Prince William’s life for nearly 25 years—and, as such, the Princess of Wales has known his younger brother, Prince Harry, for nearly the same amount of time.

Royal biographer Russell Myers—whose new book William and Catherine: The Monarchy’s New Era: The Inside Story came out in the U.S. earlier this month—said that Kate had long “witnessed” William and Harry’s “competitive nature,” and the future queen “saw it as her duty to keep the two brothers on the same team,” per an excerpt of the book shared by Marie Claire.

William, Kate, and Harry were once famously close—Harry even called Kate the sister he’d never had. Though the brothers are no longer speaking and haven’t for years, tension between the two was evident long before what Myers called the “disintegration of William and Harry’s bond.” Kate, for her part, “often acted as a peacemaker,” according to Myers.

“Her upbringing in a close-knit, loving family environment, where supporting each other was almost an unofficial family motto, spurred her actions,” Myers wrote.

He added, “Whether counseling William or having a quiet word in Harry’s ear, she saw it as her duty to keep the two brothers on the same team, as did their senior aides.”

Fellow royal biographer Katie Nicholl previously told Entertainment Tonight that Kate has acted as a “peacemaker” between William and Harry, even as recently as their grandfather Prince Philip’s 2021 funeral, one month after Harry and Meghan Markle’s bombshell interview with Oprah Winfrey.

“It’s always been my understanding that behind the scenes, Kate has tried very hard to forge a rapprochement and act as a peacemaker between William and Harry,” Nicholl said. “She loves Harry. She says that she is the sister that he never had. She has been heartbroken to see them fall out, and I think she is one of the few people, one of the few family members, who would actually be able to push the brothers together—which she did in a very subtle way, but was very effective.”

Per The Telegraph, Kate was said to be “hopeful of a reconciliation” before the Oprah interview, with a source telling the outlet, “She is certainly someone who shies away from conflict and will be hoping to soothe the tensions.” But, in recent years, her priorities have shifted.

“Catherine has far, far too much on her plate to bother about trying to rope in an estranged brother,” former BBC royal correspondent Jennie Bond said, per The Mirror. She added, “You can try playing peacemaker for so long, and it looks as though she did make some attempt to bridge the gap.”

“But in the end, your loyalty and your heart belong to your husband, and I don’t think Catherine will exert any pressure on William to hold out an olive branch to Harry unless he decides that’s what he wants,” Bond continued. “And that looks wholly unlikely for the foreseeable future.”

As Myers wrote, even after William’s anger reached new heights following the Oprah interview and Harry’s 2023 memoir Spare, Kate’s “attitude was consistently ‘this will pass,’” according to Myers. “Whenever William would get riled up about it, she would calm the situation down and bring him back to what matters most to them. That is their family and what they are doing.”