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

King Charles championed the royal family’s dedication to Commonwealth Day, calling for unity alongside Queen Camilla, Prince William and Kate Middleton at Westminster Abbey after he and Kate missed last year’s service due to their cancer treatments.

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.