The Chevalier d’Eon was born on the 5th of October 1728 in Burgundy, France. They were christened Charles-Geneviève-Louis-Auguste-André-Timothée d’Éon de Beaumont (a masculine name(s), for those unfamiliar with French aristocratic naming practices). Their family was indeed aristocratic, but they had fallen on hard times (at least by aristocratic standards). D’Eon’s father was an attorney and director of the King’s dominions. Their mother was the daughter of a Commissioner General to the French armies. As a child d’Eon excelled in their education. They moved to Paris in 1743 to complete further studies and graduated with a degree in civil law and canon law from the College Mazarin in 1749, aged 21. D’Eon then served as secretary to the intendant of Paris, secretary to the administrator of the fiscal department and royal censor for history and literature. Although d’Eon was physically androgynous, they lived publicly as a man and pursued masculine-gendered skills and occupations.
In 1756 d’Eon joined the Secret du Roi, a network of spies working for King Louis XV, without informing the government. The Secret du Roi was known to occasionally support the king’s plans in contradiction to official government policy. D’Eon records that the king sent them along with Chevalier Douglas, a Scottish Jacobite in French service, on a secret mission to meet Empress Elizabeth of Russia and conspire against the Hapsburg monarchy. At this time the English were trying to prevent French access to Empress Elizabeth by allowing only woman across the Russian border. D’Eon was able to pass as a female and cross the border unimpeded (the result of failure would likely have been execution). During the mission d’Eon was disguised as ‘Lea de Beaumont’ and they served as a maid of honour to the Russian Empress. Chavalier Douglas was eventually made French ambassador to Russia and d’Eon became secretary to the French embassy in St Petersburg. D’Eon served Chevalier Douglas and later his successor from 1756 to 1760.
D’Eon returned to France in October of 1760 and was granted a large pension. In 1761 d’Eon was made a captain of dragoons and they fought in the latter part of the Seven Years’ War. They were wounded at the Battle of Ulstrop but seem to have made a full recovery. Empress Elizabeth of Russia died in January of 1762 and the French king considered d’Eon for further work in Russia. However they were instead appointed secretary to the duc de Nivernais and sent to London to draft the peace treaty which formally ended the Seven Years’ War. The treaty was signed in February of 1763 and d’Eon was summarily rewarded. Up to this time d’Eon had not been known as ‘Chevalier’; they were awarded the Order of Saint-Louis for their service along with the title of chevalier (French for knight or nobleman). In 1763 d’Eon was made char d’affaires in London and then an interim ambassador when the duc de Nivernais returned to Paris. D’Eon used this position to their advantage in order to spy for the French king. D’Eon was able to cultivate connections with the English aristocracy by gifting them with the produce of their vineyard in Burgundy.
In October of 1763 the new French ambassador, comte de Guerchy, arrived and d’Eon was demoted in humiliating manner to the role of secretary. At this point d’Eon found themself caught between two opposing French factions; the allies of Madame de Pompadour, which included de Guerchy, and the comte de Broglie and his brother. D’Eon complained about this situation and eventually disobeyed orders to return to France. D’Eon wrote to the French king saying that de Guerchy had attempted to drug them. The French requested to extradite d’Eon but the British government refused and consequently d’Eon’s pension was stopped. In order to salvage their good-standing in London, d’Eon published much of their secret correspondence, and decried de Guerchy as unfit for his appointment. This breach of confidentiality created a huge scandal, but d’Eon had not yet published all the correspondence in his possession. The French realised that they would have to handle the situation carefully, given d’Eon still held important documents involving an invasion plan. D’Eon sued de Guerchy for attempted murder and Guerchy then sued for libel. D’Eon was declared an outlaw and went into hiding. However, they had secured the sympathy of the British people. De Guerchy found himself being jeered at in public and even had stones thrown at his home. He was eventually recalled to France. In the meantime d’Eon had written a book on public administration, which was published in Amsterdam in 1774. The king of France eventually granted d’Eon another pension, in return for withholding the invasion documents, but refused d’Eon’s request to clear their large debt. D’Eon returned to their work as a spy in London but could not return to France. Their possession of the important documents would only protect them while they stayed out of the king’s reach.
Although d’Eon had always lived publicly as a man, rumours ran around in London that they were actually female-bodied. At one point there was an even a betting pool on the London Stock Exchange regarding d’Eon’s biological sex, although it was eventually abandoned. When King Louis XV died in 1774 at the Secret du Roi was abolished, d’Eon began to negotiate a return to France from exile. A twenty-page treaty was written by a representative of the French government which allowed d’Eon to return and retain her pension, providing that they returned all correspondance regarding the Secret du Roi. It was at this point that d’Eon claimed to be biologically female, and demanded recognition as such. They claimed that they had been raised as a boy because their father was only able to inherit from his inlaws if he produced a male heir. The court of King Louis XVI complied with this demand without further examination and requested that d’Eon dress in female attire from then on, although they were still allowed to wear their insignia for the Order of Saint-Louis. D’Eon finally agreed to the treaty on condition that the king provide them with a new feminine wardrobe. D’Eon finally returned to France but for their previous actions was banished to their birthplace in Burgundy.
During the American War of Independence, d’Eon requested to join the French troops aiding the American rebels, but their banishment prevented it. In 1779 d’Eon published her memoirs, although they were ghostwritten by a friend and probably highly embellished. D’Eon returned to England in 1785. During the French Revolution d’Eon’s pension was stopped and their lands in Burgundy confiscated. Still in England, they resorted to selling personal possessions in order to remain afloat. In 1792 d’Eon wrote to the French National Assembly and offered to lead a division of female soldiers against the Habsurgs – the offer was rebuffed. Although still living as a woman, d’Eon often participated in fencing tournaments until they were seriously wounded in 1792. D’Eon then lived with a widow woman called Mrs. Cole. In 1804 d’Eon was so financially stricken that their went to debtors prison for five months. Some time after their release d’Eon suffered a fall and became paralysed. She was sadly bedridden until she died on the 21st of May 1810, aged 81 years old.
When doctors examined d’Eon’s body that noted that they had “male organs in every respect perfectly formed” alongside femininely shaped limbs and “breast round and remarkably full”. D’Eon was buried at St Pancras Old Church in London. It is unclear whether d’Eon was a transgender woman or had a non-binary or mixed gender, and it is not known whether they had any kind of intersex condition. Regardless, the Chevalier d’Eon is remembered as an intelligent and courageous person who made the most out of life’s opportunities.