A model wears the Northumberland Strawberry Leaf Tiara during the Ageless Diamonds exhibition at Christie’s in London, 1959; the tiara was stolen from the Dowager Duchess of Northumberland when her car was ambushed by thieves during the Greek state visit in 1963

The Richmond Tiara, owned by the Gordon-Lennox family, is shown in a photograph provided by local police; the tiara, which dates to 1820, was burgled from the family’s estate, Goodwood House, in January 2016