At Prince Harry and Meghan Markle’s May 19, 2018 royal wedding, it was a melding of the groom’s British background and the bride’s American background.

One difference between the two cultures, particularly at social gatherings? British couples typically sit apart, while American couples tend to sit together. For Harry and Meghan’s wedding reception for roughly 200 people at Frogmore House, the newly minted Duke and Duchess of Sussex had placed couples together—the American style. But, according to Brides—and Harry’s 2023 memoir, Spare—Prince William and Kate Middleton changed the seating chart so that they would sit apart instead.

William and Kate switching up their seats to sit at separate tables annoyed Harry, as he wrote in Spare. “For our part, we chipped in that we weren’t too pleased when Willy and Kate switched place cards and changed seats at our wedding,” Harry wrote.

“We’d followed the American tradition, placing couples next to each other, but Willy and Kate didn’t like that tradition, so their table was the only one where spouses were apart,” Harry continued. After Harry confronted William and Kate about the incident, they claimed that another person must have changed their place cards.

They also, per Harry’s account, accused Harry and Meghan of altering the seating chart at Kate’s sister Pippa Middleton’s May 20, 2017 wedding to James Matthews, almost exactly one year prior. “We hadn’t,” Harry wrote. “Much as we’d wanted to. We’d been separated by a huge flower arrangement between us, and though we’d desperately wanted to sit together, we hadn’t done a thing about it.”

“None of this airing of grievances was doing any good, I felt,” Harry added. “We weren’t getting anywhere.”

In a new royal biography by Russell Myers, William and Catherine: The Monarchy’s New Era: The Inside Story, Myers explained how Kate was a calming force for William during the release of Spare and also Harry and Meghan’s 2021 interview with Oprah Winfrey and their exit as working royals in 2020.

“While Catherine had demonstrated a steely resolve few had seen before, either publicly or in private, William was, according to several sources, absolutely seething,” Myers wrote. “He felt betrayed by Harry to the extent that he vowed never to speak to him again.”

A source close to William added that “the book reinforced his view that [Harry] was not to be trusted.”

As far as Kate went, “Her attitude was consistently, ‘This will pass,’” another source said. “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.”