Prince Harry and Meghan Markle's feud with the Prince and Princess of Wales will "never be healed", a royal author has claimed.
William and Kate were both at King Charles' Coronation along with Harry - although Meghan stayed at home with her children Prince Archie and Princess Lilibet.
It was the first time the two warring brothers had been seen at the same event since the release of Harry's controversial memoir Spare.
In the explosive book, the Duke of Sussex accused his older brother Prince William of physically attacking him during a heated row. He also dished on a disagreement between his wife Meghan and sister-in-law Kate over bridesmaids' dresses in 2018.
And now Tom Quinn, the author behind the book Gilded Youth: An Intimate History of Growing Up in the Royal Family, says the rift between the two couples is potentially too deep to fix.
He told the Express : "People I've spoken to who work for both William and Kate say this is never really going to be healed.
"Privately there's a lot more anger than there is publicly, especially about the accusation William physically assaulted Harry. Apparently, William is furious."
It comes after a body language expert pinpointed the exact moment during Saturday's Coronation that Harry gave William a "thunderous look".
The Duke of Sussex was seated in the third row for the crowning of Charles and his stepmother the Queen in Westminster Abbey and was placed two rows behind his brother.
Harry chatted to his cousin Princess Beatrice and her husband Edoardo Mapelli Mozzi as he entered the church on Saturday in the drizzling UK rain.
While sat down, he was seen looking in his brother's direction, in what behavioural expert Judi James described as a "telling moment".
She told Fabulous : "Despite his act of bravado, there were some more telling moments and expressions from Harry, like this pensive one when he seemed to glance across at William.
"William is clearly not about to look back here and Harry's severe side-eye glance suggests he's sneaking this thunderous look almost unintentionally.
"When we tell ourselves not to do something the brain only tends to hear the suggestion without processing the 'don't' command, suggesting the more Harry was telling himself not to look across at his brother the more he couldn't stop."
After the service, there was no time for the brothers to reconcile as Harry headed straight to Heathrow via a reported brief stop at Buckingham Palace to race back to California.
He was pictured at the London airport still in his suit and medals before jetting back to his home, where son Archie was celebrating his fourth birthday.
