Princess Anne switched up her hairstyle for the glam state banquet on July 8

It was a style surprise for the Princess Royal, who has regularly worn a bouffant since the mid-1980s

Princess Anne, 74, topped the look with her diamond Festoon Tiara

Princess Anne switched up her signature style in a shocking twist — of her hair!

On July 8, King Charles' sister wore her hair in a new way for the first time in decades at the state banquet honoring French President Emmanuel Macron and his wife, Brigitte, at Windsor Castle.

The diplomatic dinner capped the first night of the couple's three-day state visit to the U.K. and Princess Anne, 74, served a style surprise by sporting a new hairstyle.

The Princess Royal wore her hair in a chignon in lieu of a bouffant, deviating from the voluminous hairdo that's considered a hallmark of her signature style.

Cameras caught a shot of the back of her head as she arrived behind Prince William and Kate Middleton, showing it swept back in a different way than she usually wears it.

Princess Anne topped the surprise style with the diamond Festoon Tiara, adding some glimmer with the sparkler she's owned since 1973.

Queen Elizabeth's only daughter started wearing her hair in a bouffant in the mid-1980s and never looked back. The Princess Royal seemingly adopted the style as her signature and has continuously worn her hair that way for public appearances until the present day.