Princess Diana, Camilla Parker-Bowles Had Bathroom Warfare, Sources Say

Princess Diana and Camilla Parker-Bowles had such a rough relationship that they reportedly attacked each other in their own bathrooms.

According to the late Princess of Wales' friend Lana Marks, in the 2001 book "Diana: Story of a Princess," Princess Diana had "unflattering cartoons" of the Duchess of Cornwall in her restroom.

"Diana's way of dealing with [her feud with Camilla] was putting an unflattering cartoon of Camilla in her bathroom," Marks said (via Vanity Fair).

The publication noted that Princes William and Harry's mom also did the same to Elton John when they had a disagreement. "Oh, he's in the bathroom with Camilla," Princess Diana reportedly said.

Tom Bower, author of "Rebel Prince: The Power, Passion, and Defiance of Prince Charles," also revealed that Camilla did the same to Princess Diana.

"Indeed, Camilla's true feelings about Diana could be gleaned simply by asking to use the guest lavatory at her home, Ray Mill, in Wiltshire. While Charles's loo in nearby Highgrove featured cartoons of himself, her own was festooned with unflattering cartoons of his wife," Bower wrote.

In the same book, Bower claimed that Camilla called Princess Diana a "mouse" and "mad cow." The investigative journalist added that Prince Charles and Camilla struggled in their battle with Princess Diana because the public's sympathy was firmly with the latter, especially after her recorded Panorama interview leaked.

"Well, there were three of us in this marriage, so it was a bit crowded," Princess Diana said in the clip, alluding to Prince Charles and Camilla's affair.

Bower also wrote that even Queen Elizabeth II did not approve of Prince Charles and Camilla's relationship even when both were already divorced. In fact, Her Majesty did not want to see Camilla in any function or talk about her.

However, the Duke and Duchess of Cornwall reportedly fought back by plotting a way to regain their good reputation. Prince Charles apparently signed an agreement with Penny Junor, a journalist, to write a sympathetic book about Camilla.

In addition, Camilla hosted a fundraiser for the National Osteoporosis Society to transform her from royal mistress to suitable wife for the future king. She also worked with Mark Bolland to "demythologise Diana by portraying her as a manipulative hysteric."

Bower claimed that Prince Charles and Camilla eventually won their battle as they were seen in various high-profile parties together. In addition, they finally convinced the queen to allow them to get married. Prince Charles and Camilla had a civil wedding in 2005.