The Grand Duchess Vladimir, aka Maria Pavlovna, in 1903. She would go into exile in 1917 and never regain her Cartier pieces, which included a black pearl and diamond tiara, the sapphire and diamond tiara, as well as her collection of about 244 jewels. She asked her friend Albert Stopford, a British citizen/art dealer/secret agent, to smuggle them out of the country for her when Russia rebelled against the Romanov dynasty. Stopford, who literally had to sneak into the Vladimir palace, hid them in the bottom of his travel trunks. After spending years in a bank vault in London (Pavlovna died before ever getting them back), Cartier got the jewels back — today Queen Elizabeth II owns the black pearl and diamond tiara.