The French Blue was the prized possession of King Louis XIV. It was a diamond specially cut to produce an image of a sun when mounted on a gold background. Louie was the Sun King after all. It was stolen in the French Revolution, recut and found its way to England where it resurfaced in 1812.
Eventually it was purchased by Thomas Hope, a rich British/Dutch banker better known for writing the 19th century bestseller Anastasius. Hope willed it to his grandson Henry Francis Pelham-Clinton Hope who married May Yohe, an American concert hall singer who ran off on him after his bankruptcy.
Take note Prince Harry.
Hope sold the diamond in 1902 to pay off debts. It was owned by a Turkish diamond collector, and various jewelry merchants including Pierre Cartier who eventually sold it to Washington D.C. socialite Evalyn Walsh McLean, who as “Missus Ned McLean,” is name-checked in Cole Porter’s “Anything Goes”.
She died in 1947 after much tragedy and her trust sold it to jeweler Harry Winston who donated it to the Smithsonian Institution where it is displayed at the National Museum of Natural History.