Empress Eugénie (diamond)

As a minister of the Empress, Potemkin acquired a large collection of jewellery, which on his death in 1791 was inherited by his niece, Countess Alexandra Branicka.

The diamond was eventually bought from Princess Bagration by the French Emperor Napoléon III as a bridal gift for his Empress Eugénie de Montijo, after whom the stone was then renamed.

After losing the Franco-Prussian War of 1870-71 and surrendering to the Germans, Napoléon III was deposed and France proclaimed the Third Republic.

The family soon found that they were short of cash and so she reluctantly agreed to sell various items, including the Eugénie Diamond.

In 1872, the auction house Christie's sold the jewel to Malhār Rāo, the Gaekwad of Baroda, a princely state in present-day Gujarat, India, for the sum of 150,000 rupees (about £12,000).