Prince Charles was reportedly livid at his brother Prince Edward after he broke a filming embargo on Prince William back in 2001.
Edward owns a media company called Ardent and they were filming a documentary in the university town of St Andrews, where William attended school.
WATCH: Prince Charles called Prince Edward an 'IDIOT'
Charles was said to be raging, with the incident bringing to light exactly how the royal family would manage both royal and commercial duties.
However a royal biographer claims it was Charles who was viewed as the bad guy by Prince Philip, Prince Edward and his wife Sophie, Countess of Wessex, because he portrayed them in a bad light.
Royal biographer Penny Junor discussed the incident in her 2005 book “The Firm”.
“The Wessexes felt particularly aggrieved, as did the Duke of Edinburgh,” said Penny.
She continued: “The story blew up into a major attack on Prince Edward and his competence as a filmmaker, and ran for some days.
“Then a further report claimed that Prince Philip, in support of his youngest son, thought William was being ‘overprotected’ by his father and that he had ‘overreacted’ to the Ardent film crew.”
Meanwhile, another royal expert has revealed why Queen Elizabeth’s four children are not close.
Speaking on New Idea’s Royals podcast, Angela Mollard says Prince Charles, Princess Anne, Prince Andrew and Prince Edward are “very different”.
Podcast host Smita Mistry quizzed the royal expert: “It’s almost like the Queen had two sets of children isn’t it?”
“That’s right, she had Charles and Anne, then a decade later had Andrew and Edward, so it’s almost like two distinct families,” Mollard replied.
She continued: “They’re very different, all four of them.
“You’ve got Anne, who’s incredibly strong-willed and forthright. She gets on very well with Prince Philip, she’s his favourite."
“Charles, who is a softer, gentler character who really did need better parenting, he needed closer parenting.”
The royal foursome were last seen together in June at the Trooping the Colour.