Princess Kate Middleton Commonwealth Day 2023
LONDON, ENGLAND – MARCH 13: Prince William, Prince of Wales and Catherine, Princess of Wales attend the 2023 Commonwealth Day Service at Westminster Abbey on March 13, 2023 in London, England. (Photo by Samir Hussein/WireImage)

On Monday, Princess Kate Middleton and Prince William returned to their wedding venue, Westminster Abbey, to attend to royal duties at the Commonwealth Day service.

Dressing for the formal occasion, the princess wore a navy set with white embroidery by Erdem, consisting of a fitted peplum jacket and a midi trumpet skirt. The look, fresh from the designer’s Pre-Fall 2023 collection, was complimented by a wide-brimmed hat and suede Gianvito Rossi pumps that matched her Emmy London clutch perfectly.

Her hair sat in a low chignon while her makeup was kept simple, with dark eyeliner drawing focus to her eyes.

Heirlooms took the polished look to princess level. Her sapphire-and-diamond engagement ring and matching flower earrings — both pieces previously owned by her late mother-in-law Princess Diana — were a no-brainer with the all-blue ensemble. But a diamond brooch that shone with sapphires and diamonds certainly stole the show.

Known as the Queen Alexandra’s Three Feathers Brooch or the Prince of Wales Brooch, the piece — which Middleton wore for the first time last year — boasts a pretty impressive history.

Worth an estimated $600,000, it dates back to 1863 when the future King Edward VII married Princess Alexandra of Denmark. It’s been passed on to members of the royal family ever since and was even owned by Princess Diana and Queen Consort Camilla Parker Bowles before being gifted to Princess Kate Middleton by King Charles.

Prince William and Kate Middleton with King Charles and Queen Camilla
LONDON, ENGLAND – MARCH 13: King Charles III, Camilla, Queen Consort, Prince William, Prince of Wales, Catherine, Princess of Wales, Prince Edward, Duke of Edinburgh and Sophie, Duchess of Edinburgh attend the annual Commonwealth Day Service at Westminster Abbey on March 13, 2023 in London, England. (Photo by Hannah McKay – WPA Pool/ Getty Images)

The appearance comes after rumors have been swirling about King Charles’ imminent coronation. More than 2,000 attendees are expected to attend the event at Westminster Abbey on May 6, making it the grandest royal event to take place in several decades.

Set to be more scaled-back than coronations of the past — the late Queen Elizabeth’s hosted around 8,000 attendees in 1953 — the guest list is of high concern, with many speculating whether or not Meghan Markle and Prince Harry will be there in support.

Earlier this month, a representative for the Duke and Duchess of Sussex confirmed that the couple had received an invite to the coronation, but did not disclose the status of their RSVP. Though rumors of family tension have always been quashed by spokespeople, the Sussex’s two children, Prince Archie, 3, and Princess Lilibet, 21 months, were left off the invite list due to their age.

Supporting Charles and Camilla will be the rest of the working royals, including the Prince and Princess of Wales, William and Catherine, as well as their children, Prince George, Princess Charlotte and Prince Louis.