Élisabeth Louise Vigée Le Brun on Wikimedia

It’s 1772, and King Louis XV is desperate to impress his mistress, Madame du Barry, with the ultimate gift to signify his affection. 

So, he commissions Parisian jewelers Boehmer and Bassenge to create a diamond necklace that would no doubt swoop Madame du Barry right off her feet. And that's exactly what they did! Worth 1.6 million livres—roughly $15 million in today's money—Boehmer and Bassenge did exactly what King Louis XV asked. But their effort was in vain. 

The Most Expensive Gift That Never Was

The necklace featured seventeen massive diamonds, each nearly the size of hazelnuts, wrapped in three festoons with dangling pendants. However, Louis XV died of smallpox before the necklace was finished, and his grandson Louis XVI banished du Barry from court. The jewelers were stuck with an impossibly expensive necklace and no buyer. 

They tried selling it to the new queen, Marie Antoinette, multiple times. In 1778, Louis XVI offered it to his wife, but she refused, allegedly saying France needed warships more than necklaces. She turned it down again in 1781. 

The Con That Fooled A Cardinal

Enter Jeanne de Valois-Saint-Rémy, a con artist claiming royal blood who called herself the Comtesse de la Motte. She set her sights on Cardinal de Rohan, a wealthy former ambassador desperate to win back Marie Antoinette's favor after spreading unflattering gossip about her. Jeanne convinced Rohan that she had the queen's ear and could help restore his reputation.

What followed was an elaborate scheme involving forged letters supposedly from Marie Antoinette, written in increasingly romantic tones. Rohan became convinced the queen was in love with him. In August 1784, Jeanne arranged a secret nighttime meeting in the gardens of Versailles. 

The cardinal met a woman he believed was Marie Antoinette—but it was actually a woman named Nicole Le Guay d'Oliva, hired because she resembled the queen. The imposter accepted a rose and promised to forgive past grievances. Riding high on this delusion, Rohan became Jeanne's personal bank, giving her massive loans.

Then Jeanne told Rohan that Marie Antoinette secretly wanted to buy the diamond necklace but needed him to act as intermediary. On January 21, 1785, Rohan negotiated the purchase—2 million livres, paid in installments. He showed the jeweler's authorization in the queen's handwriting, collected the necklace, and delivered it to Jeanne's house, where a fake valet whisked it away.

The Trial That Toppled A Throne

Château de Breteuil on Wikimedia

When payment came due, everything unraveled. The jewelers complained to Marie Antoinette, who had no idea what they were talking about. Arrests followed in August 1785, with Rohan dramatically seized in the Hall of Mirrors at Versailles on the feast of the Assumption of Mary, while the court waited to attend the chapel.

The sensational trial in 1786 acquitted Rohan but convicted Jeanne, who was whipped, branded with a "V" for thief, and imprisoned. She escaped a year later, disguised as a boy, and fled to London, where she published memoirs repeating her lies about the queen.

Despite being proven innocent, Marie Antoinette's reputation was demolished. The public believed she'd orchestrated the scheme, seeing her as a manipulative spendthrift more interested in vanity than France's welfare. Her public appearances essentially ceased.