Middleton — who scaled her royal schedule back last year due to her cancer diagnosis — joined Prince William, King Charles, Queen Camilla, Princess Anne, Prince Richard, Duke of Gloucester and Birgitte, the Duchess of Gloucester, for the commemoration.

King Charles and Queen Camilla were joined by the Prince and Princess of Wales, Princess Anne, and the Duke and Duchess of Gloucester at Westminster Abbey.

Kate Middleton is set to attend the Commonwealth Day Service, a key event for the royal family. All about the Princess of Wales' RSVP next week.

Kate Middleton attended the Commonwealth Day Service, marking her first appearance at the event in two years after undergoing cancer treatment. Dressed in a red Catherine Walker dress, her presence signified her return to full royal duties following her remission announcement in January.