REX USA/Ken McKay/ITVJoan Rivers teased the royal family for decades, but thankfully, they were in on the joke.
The Fashion Police host was "surrounded by family and close friends" at the time of her death Thursday.
In a statement released to E! News Friday morning, Prince Charles and Camilla Parker-Bowles offered their condolences. "The Prince of Wales and The Duchess of Cornwall are deeply saddened to hear of the death of Joan Rivers," a Clarence House spokesperson said. His Royal Highness, 65, added that the comedy icon, 81, "was an extraordinary woman with an original and indefatigable spirit, an unstoppable sense of humor and an enormous zest for life. She will be hugely missed and utterly irreplaceable."
Rivers was a guest at the couple's Apr. 9, 2005 wedding. She was one of four Americans on the guest list.
She also performed for Their Royal Highnesses, plus Charles' sons Prince William and Prince Harry, at the "We Are Most Amused" comedy gala, in aid of The Prince's Trust, for Charles' 60th birthday in 2008.
Rivers praised the royals for being good sports. "Charles and Camilla have a great sense of humor. He is so charming, so humorous. All the passions that everyone used to laugh at him for—organic food, architecture, talking to the flowers—we're all into those things now," she said in 2011. "He is so far ahead of his time, and I think he will be a very good monarch. He is a very smart man and I adore him."
When Kate Middleton was pregnant, she didn't give Charles tips for being a grandparent. "When you are dealing with the royals, you have to know what line you cannot go over," she explained to E! News.