King Charles and Queen Camilla have been married and stable for a while now, so for some, it’s easy to forget that their relationship was a scandal for many years. In fact, for decades, there was the notion that King Charles could not marry Camilla, as the public would not accept her as Queen. Things didn’t really turn out that way, but the rumors about their affair and how Prince Diana reacted have still been part of the narrative for years.

Now, a new book about King Charles, titled Rebel King: The Making of a Monarch by Tom Bower, is disclosing a tense encounter between King Charles, Queen Camilla, and the king’s then-wife, Princess Diana. The confrontation took place at a birthday party in 1989, long before the affair between Charles and Camilla and the marital issues between Charles and Diana were even public knowledge.

More from StyleCaster

Related: Here’s what each royal inherited from Queen Elizabeth

It all reportedly took place when Diana arrived unexpectedly at a party that Camilla and her then-husband, Andrew Parker Bowles, were attending. Bower writes, “Diana arrived unexpectedly at a birthday party at Annabel Goldsmith’s house in Ham, near Richmond. Charles was with Diana, while both the Parker Bowleses were already there. As the room fell suddenly silent, Diana challenged Camilla to leave Charles alone.”

Camilla reportedly “controlled her fury” and told Diana that her behavior was “unacceptable in a private house.” That’s not all, according to Bower, “The princess, she said was poorly placed to complain. While Camilla confined herself to a single, conventional relationship, Diana, she had been told by friends, was “working her way through the life guards.”

Afterwards, each side placed the blame on the other. “’Camilla’s intimates blamed the bruising encounter on Diana for creating “such a public scene”. Others accused Camilla of b—hiness.”

Queen Camilla & Princess Diana's Relationship Amid Charles Cheating Rumors

Queen Camilla & Princess Diana’s Relationship Amid Charles Cheating Rumors

Rebel King: The Making of a Monarch

$12.00 Buy Now On Amazon

Details of the relationship between King Charles and Queen Camilla are well-known. Camilla met her first husband, Andrew Parker Bowles, before Charles, and the two had even broken up by the time she met Charles. However, Queen Elizabeth II and the rest of the family did not approve of the relationship.

Reports indicate the Queen Mother organized a secret meeting between Andrew and Camilla’s families, and a wedding date was agreed upon. The couple married in 1973. But the two remained friends and even reportedly rekindled their relationship in 1980. Charles and Diana married in 1981, which means Charles and Camilla were already back together by that time.

Camilla was reportedly a big issue in the marriage between Charles and Diana, with Princess Diana even saying “there were three of us in this marriage” in a very famous BBC interview in 1995.

But recent revelations make it clear that not only was this so since the beginning, Princess Diana knew and even tried to do something about it at some point. Charles and Diana separated in 1992 and divorced in 1996. Princess Diana would pass away in a car accident in 1997. Charles and Camilla would then finally tie the knot in 2005.

Best of StyleCaster

Sign up for Stylecaster’s Newsletter. For the latest news, follow us on Facebook, Twitter, and Instagram.