The Princess Royal and the Duchess of Edinburgh were among the senior royals to attend the glittering state banquet for the Emir of Qatar at Buckingham Palace on Tuesday.
The white-tie dress code called for evening gowns and tiaras, but the two royal ladies also debuted another important accessory on the night.
Princess Anne, 74, and Sophie, 59, wore King Charles' Royal Family Order for the first time.
The badge is a miniature of the monarch, bordered by diamonds and attached to a pale blue silk ribbon.
The honour is bestowed on female members of the royal family by the monarch. It is usually worn pinned to the dress of the recipient on the left shoulder.
Anne and Sophie also wore Queen Elizabeth II's Royal Family Order, which is suspended from a yellow silk ribbon.
King Charles' Royal Family Order was worn for the first time by Queen Camilla at the Japanese state banquet in June.
It's likely that the Princess of Wales also has the new honour but she missed the Japanese and Qatari state banquets, and the diplomatic reception this year.
Kate became the first British royal to wear the honour made with glass instead of traditional ivory when she was awarded it in 2017. This significant change is likely to be in support of Prince William's work around conservation and his commitment to end the ivory trade.
Charles' is made from oil on polymin, a synthetic replacement for the ivory used in previous royal family orders.
The late Princess Margaret often displayed her three Royal Family Orders – King George V, King George VI and Queen Elizabeth II.
It's likely that the Princess of Wales will end up with three of her own in future – Queen Elizabeth II, King Charles III and when he ascends the throne, that of her husband, Prince William.