The Princess of Wales honored her father-in-law, King Charles, in the traditional way and made a subtle homage to Queen Elizabeth during Monday’s church service.

Kate Middleton is back at the Commonwealth Day Service after missing it last year before announcing that she was undergoing treatment for cancer.

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.

Kate Middleton continues to set an impressive example in sustainable fashion by re-wearing her elegant red Catherine Walker dress. By accessorizing with royal heirlooms and elegant pieces for the Commonwealth Day Service,

The Princess of Wales joined members of the royal family at Westminster Abbey on Monday, March 10, to celebrate Commonwealth Day. As part of the service, Kate and Prince William processed behind King Charles and Queen Camilla. They were followed by Anne, Princess Royal, as well as the Duke and Duchess of Gloucester.

Kate Middleton paid a subtle tribute to Princess Diana and Queen Elizabeth II with her fashion as she attended the Commonwealth Day celebrations in London March 10.