Princess Diana and Queen Camilla Once Had a Tense Encounter That Silenced an Entire Birthday Party

The royal family is never short on drama or immune from gossip, but few moments of modern royal scandal can compare to the fallout from King Charles' affair with his now-wife, Queen Camilla, during his first marriage, to Princess Diana.

While the general public did learn about all of the scandalous details until the early 1990s, some members of the royal family's social circle got a sneak peek at the drama during a birthday party in 1989.

In his book Rebel King: The Making of a Monarch, royal author Tom Bower details a tense moment when Diana and Camilla (who was still married to her first husband, Andrew Parker Bowles, at the time) unexpectedly ran into each other at a birthday party for Lady Annabel Goldsmith.

According to excerpts from the book quoted by the Daily Mail, things quickly turned tense when "Diana arrived unexpectedly" at the party.

"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," according to the Daily Mail's excerpt.

Camilla reportedly "controlled her fury" at Diana during the incident—but still made a point to tell the Princess of Wales that her behavior was "unacceptable in a private house."

"The princess, she said was poorly placed to complain," Bower wrote. "While Camilla confined herself to a single, conventional relationship, Diana, she had been told by friends, was 'working her way through the life guards.'"

The confrontation drew mixed reactions, apparently. While Bower wrote that "Camilla's intimates blamed the bruising encounter on Diana for creating 'such a public scene,'" he added that "others accused Camilla of b*tchiness."

As the Daily Mail notes, Diana's negative feelings about Camilla's relationship with Charles weren't without merit at this time, since by 1989, Charles and Camilla had been spending "more and more time together." In addition to vacationing together in Turkey (along with Andrew Parker Bowles), Camilla had been spotted wearing a bracelet with the initials "G" and "F," in a nod to "Gladys and Fred," the nicknames Camilla and Charles used with each other.

After she and Charles separated in 1992, Diana officially made the affair part of the public record when she mentioned it in her authorized biography, Diana: Her True Story.

Although it was no secret that Charles and Camilla began seeing each other after their respective divorces in the mid-1990s (Camilla and Andrew divorced in 1995 and Charles and Diana's divorce became official in 1996), they kept their relationship low-key at first, not making their first public appearance together until 1999 and marrying in a small civil ceremony in 2005.