Original sixties supermodel Twiggy is the latest celebrity to receive a damehood, awarded with the prestigious accolade for her services to fashion, charity and the arts.
Not one to put a fashion foot wrong, the 69-year-old met Prince Charles in a chic Â£1,645 co-ord by Stella McCartney â€“ a lesson in diplomatic dressing.
But the history-making moment left us wondering, what on earth does one wear for a meeting at Buckingham Palace?
In arguably one of the most famous British-royalty-meets-pop-royalty photographs of all time,Â a sunglasses-clad Kanye West is seen partying with Princes Harry and William back in 2007.
While Lady Gaga certainly wasnâ€™t going to follow protocol when curtseying to the Queen during her more boundary-pushing heyday.
From Victoria Beckham to One Direction, hereâ€™s what some of your favourite celebrities wore to meet the Windsor clan.