The tiara was then gifted to the Queen when she was still known as Princess Elizabeth, to mark her 18th birthday.

Several members of the Royal Family wore the tiara before Kate did at her wedding, including the Queen’s sister Princess Margaret.

The Queen’s daughter, Princess Anne, has also worn the tiara in public, most notably during her tour of New Zealand in 1970.

But the Queen has not been publicly pictured wearing the tiara during her reign.