Those present included designers Zandra Rhodes, Julien MacDonald and Betty Jackson and raven-haired supermodel Erin O'Connor, who confessed to being nervous about speaking to the monarch.
"I'm not one for being over-excited, but she's such an important lady," said the 32-year-old, pretty in a black silk shirt with oversize bow, printed jacket and flats.
It wasn't a first for Sixties icon Twiggy – who was wearing a Stella McCartney dress with a print by her own daughter Carly. She said: "I've been to the Palace a few times and met the Queen before and she's lovely.
Sophie Dahl was also full of praise for the British sovereign, on elegant form in a floral-print Angela Kelly suit.
"The Queen is my icon in general," said the model-turned-cookery show host. "I have embraced her use of matching shoes and handbag since I was 16. I think she looks marvellous."
Other guests at the reception, where students from the Royal College of Art exhibited a display of contemporary clothing, included Yasmin LeBon and Duran Duran star husband Simon.
Vivienne Westwood was unable to attend due to ill health, however.