Prince Harry has a reputation for getting angry - and his brother William can also unleash his temper, Camilla has revealed.
After her marriage to Prince Charles in 2005, William's stepmother was surprised at discovering an unexpected side to the prince, saying, "The boy's got a temper!", according to royal historian Robert Lacey.
And Camilla was often horrified that William would "rant and rave" at Charles, even if she was present.
According to her, William did all the shouting while Charles would "meekly submit".
William would hold nothing back, Lacey said - "summoning up a wrath to match the importance that he attaches to his challenging role as the future king."
If Charles failed to live up to William's view of what being a royal entails, then the younger man would release his rage.
And it seems Charles didn't rate as a wonderful parent in William's eyes. When marking the 20th anniversary of Princess Diana's death in 2017, William refused to make any comments about Charles's parenting.
While his aides begged him to compliment his father when talking to media ahead of the ITV doco Diana, Our Mother, he refused.
"William simply wasn't prepared to pretend that the workaholic, ever-worrying Charles had made good on all the hands-on parenting that he'd promised," Lacey wrote.
But in recent times, especially after Harry's departure with Meghan, father and son have grown much closer again.
Charles and William appreciate that they need to work together for the sake of the monarchy.
Their quarrels are now said to be in the past.
Lacey's book Battle of Brothers reveals details about the breakdown in the relationship between Prince Harry and Prince William, set to be released soon.