Royals re-wearing gowns is old news by now but, before Kate's penchant for her Alexander McQueen coats and Meghan's commitment to recycling her dresses, Denmark's Crown Princess Mary made it more acceptable for a royal to revisit an outfit.
The Princess, who married Crown Prince Frederik in 2004, was formerly an advertising executive from Sydney, Australia and paved the way for Kate Middleton and Meghan Markle, showing the world that someone from a "normal" background could flourish in a royal position.
But perhaps most influential was her ease with re-wearing outfits, which seems commonplace now but was unusual just a few years ago.
Stepping out in two of her favourite couture pieces over the course of the two-day royal New Year celebrations, the veteran style icon once again championed sustainable fashion.
For New Year's Eve, the Princess wore the same breathtaking red velvet gown that she had worn for three New Year's Eve celebrations. She wore the long-sleeved, full-length dress for the first time while pregnant in 2007, and has since tailored and updated it each year.
Adding some festive sparkle with a diamond-and-ruby-encrusted belt, the Ruby Parure Tiara and Order of the Elephant medal, the country's oldest and most distinguished royal order of chivalry. With matching burgundy court shoes and fresh, rosy makeup, the Princess looked elegant and romantic.
The following day festivities continued, with Mary recycling another couture gown - a full-length white medieval gown that she has worn three times in the last five years. Paired with white gloves, matching pearl earrings and necklace and a chic cream coat, Mary perfected winter whites.
The elegant gown by Birgit Hallstein was also Mary's go-to for the New Year celebrations in 2015 and 2016, suggesting that tradition is as important to the royal as sustainability.
