The Affair of the Diamond Necklace — A 1785 Confidence Trick That Damaged a Throne
The Affair of the Diamond Necklace — A 1785 Confidence Trick That Damaged a Throne
Cardinal de Rohan, Jeanne de la Motte, and the Parisian trial that turned a fraud into a political event
The Affair of the Diamond Necklace (l'Affaire du Collier) is the 1785 scandal in which Cardinal Louis de Rohan, Grand Almoner of France, was deceived by a confidence trickster into acquiring a 1.6-million-livre diamond necklace on the supposed instructions of Queen Marie Antoinette. The fraud was discovered when the court jewellers came to claim payment, and the resulting trial in 1786 produced a verdict — Rohan acquitted, the queen humiliated by association — that contemporaries and later historians identified as one of the events that shifted French public opinion against the monarchy in the years immediately preceding the Revolution.
The participants
Three figures sit at the centre of the affair. Cardinal Louis de Rohan, formerly French ambassador to Vienna and a senior figure in the French church, had fallen out of favour with the queen during his Vienna posting and was actively seeking restoration to her good graces. Jeanne de Saint-Rémy de Valois, Comtesse de la Motte, was a minor descendant of an illegitimate Valois line, then living in straitened circumstances in Paris with her husband Nicolas. The court jewellers Charles-Auguste Boehmer and Paul Bassenge had assembled, on speculation, the most expensive diamond necklace ever produced in France — a piece they had repeatedly failed to sell.
The deception
De la Motte cultivated Rohan's confidence over the course of 1784 by representing herself as a confidante of the queen. She produced forged letters purportedly from Marie Antoinette to the cardinal, and in August 1784 staged the celebrated Bosquet de Vénus episode at Versailles, in which a prostitute named Nicole Le Guay d'Oliva, dressed as the queen and prompted to speak only briefly, met Rohan at night in the palace gardens to confirm her favour. Rohan came away convinced that the queen had reconciled with him in confidence and that he was now her trusted intermediary.
In January 1785 de la Motte informed Rohan that the queen wished to acquire the Boehmer and Bassenge necklace in secret, paying in instalments through him. A forged contract — signed Marie Antoinette de France, a signature any French courtier would have recognised as illegitimate (queens of France signed only with their given names) — was produced as authorisation. On 1 February 1785 Rohan acquired the necklace from Boehmer on credit and delivered it the same evening to de la Motte's husband, Nicolas, who left immediately for London with the dismantled stones.
Discovery
The first instalment of payment fell due in July 1785. When Boehmer attempted to confirm the arrangement with the queen — through her household, not directly — the fraud became apparent. Marie Antoinette, on learning of it, demanded a full accounting. Louis XVI ordered Rohan's arrest on 15 August 1785, in his ceremonial robes at Versailles before he was due to celebrate the Feast of the Assumption. The arrest of a sitting cardinal of the French church in the palace was itself a political event of the first order.
The trial (1786)
The case was tried before the Parlement of Paris between December 1785 and May 1786. Rohan was acquitted on 31 May 1786, the court accepting his defence that he had been the victim of fraud. Jeanne de la Motte was found guilty of fraud, sentenced to be branded with the letter V (for voleuse) and imprisoned for life in the Salpêtrière; she escaped within a year and fled to London, where she published memoirs accusing the queen of involvement. Nicholas de la Motte was sentenced in absentia. The prostitute Nicole d'Oliva was acquitted as an unwitting participant. The necklace itself was never recovered.
Political consequence
The acquittal of Rohan was widely read as a verdict against the queen. The Parlement of Paris, in finding for the cardinal, effectively endorsed the proposition that the queen could plausibly have been the instigator of a secret transaction with a man she was known to dislike. The aristocratic and clerical sympathy with Rohan — celebrated in Paris on his release — demonstrated that significant portions of French society would believe almost any accusation against Marie Antoinette. Napoleon's observation that the queen's death must be dated from the Diamond Necklace trial reflects the consensus of subsequent historical opinion.
Historiography
The affair has been subject to extensive historical scholarship from the early 19th century onward. Modern accounts uniformly accept Marie Antoinette's non-involvement; the question that has interested historians is the political and cultural environment in which the public was so willing to believe the contrary. Sarah Maza's Private Lives and Public Affairs (1993) places the affair within a wider analysis of late-18th-century French scandal literature.
In the trade
For the jewellery trade, the affair is the canonical example of fraud in a high-value, lightly documented private transaction — a category of risk that has not entirely disappeared from contemporary practice. The case also illustrates the diamond market's capacity to absorb large quantities of high-value stones quickly and largely without trace once they enter the trade in dismantled form.