Kate, the Princess of Wales, joined her husband Prince William, King Charles III and Queen Camilla on Tuesday as they kicked off France's state visit to the U.K. The royals gathered at RAF Northolt in Windsor, England, to welcome French President Emmanuel Macron and his wife Brigitte, at the start of their state visit.

Kate Middleton and Prince William helped start the France state visit to the U.K. by welcoming President Emmanuel Macron and his wife, Brigitte Macron, before meeting up with King Charles and Queen Camilla.

As President Emmanuel Macron and his wife Bridgette Macron were welcomed by Prince William and Princess Kate for their state visit, fans quickly spotted a hidden detail in the royal's outfit