Experts say this is probably due to the fact she received the tiara at a time when Britain was at war when it wouldn't have been appropriate to wear such a piece. After her marriage to Prince Philip .

Sophie, the Duchess of Edinburgh, marked the occasion on 20th January, and is celebrating with a black tie bash ...

The Duchess of Edinburgh beamed ... and wore the Wessex aquamarine tiara. Other Royals in attendance included King Charles, Queen Camilla, Princess Anne, Prince William, Sir Timothy Laurence ...