The Princess curtseyed to her father-in-law - but did not embrace him at the service, unlike her husband, Prince William. And it turns out there's a very important reason

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.

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.