Kate Middleton’s St. Patrick’s Day Good Luck Charm Goes Way Back

On St. Patrick's Day this year, Kate Middleton broke one fashion tradition, and kept another going strong. For the past two years, the Duchess of Cambridge has worn the same fit-and-flare Emilia Wickstead coat to celebrate the Irish holiday, but this year she switched it up in an even more flattering green double-breasted Hobbs Persephone wool coat. She completed the look with matching green pumps and a Gina Foster hat (the same one she wore last Christmas), and, perhaps most significantly, a recognizable sparkling Cartier shamrock brooch.

The gold three-leaf shamrock pin, adorned with an emerald stone in the middle, was first worn by Queen Alexandra in 1901. It was then that Alexandra began the tradition of the shamrock ceremony, presenting lucky sprigs to 1st Battalion Irish Guards. (This year Middleton also presented one to the battalion's mascot, Domhnall the Irish wolfhound.) Also of note: The Cartier piece, traditionally worn on the left side, is not actually owned by the royal family—it belongs to the Irish Guards regiment, and has been lent out to the queen mother, Princess Anne, and eventually the Duchess of Cambridge for events.

The first time Middleton wore the brooch was when she attended the Irish Guards Afghanistan Operational Medals Parade at Victoria Barracks on June 25, 2011, in Windsor, England. In 2012 the duchess adopted the role as presenter of shamrocks, and she's worn the brooch on St. Patrick's Day every year since.