Charles-Geneviève-Louis-Auguste-André-Timothée d’Éon de Beaumont—known more simply as the Chevalier d’Éon—was a French soldier, diplomat, and spy who settled in London, living from 1762-1777 as a man and from 1786-1810 as a woman.

Born to a poor noble family in Burgundy and raised as a boy, d’Éon attended law school in Paris before joining the civil service. He was quickly was promoted through the ranks until appointed ambassador to Russia in 1756.

Sent to the court of Empress Elizabeth in Russia, d’Éon may have at that time already been working as a  spy for Louis XV, tasked with advancing French interests in eastern Europe;  he likely also attended the famous regular Tuesday night “drag balls” of the Russian court where—at Elizabeth’s command—women dressed as men and men as women. In one version of the story, d’Éon actually arrived and lived in Russia disguised as a woman, since the British had endeavored to restrict travel there to only women and children.

In 1756, when the Seven Years’ War swept all of Europe into turmoil, d’Éon returned to France to serve as a soldier in the French army. Toward the end of the war,  he was appointed as a secretary to the French ambassador to Great Britain (France’s enemy in the conflict), where he helped negotiate the Peace of Paris, which ended the war and restored peace to the continent.

In spite of the treaty, d’Éon was given a secret mission to scout the British coast in preparation for a French invasion; however, his relationship with the French government had begun to deteriorate; a new ambassador had demoted him to the rank of secretary and he became embroiled in factional conflict. He reacted by scandalously publishing secret correspondence and threatening to reveal the invasion plans, eventually securing a pension from the French king in exchange for his silence.

As a condition of this arrangement and of his return to and pardon in France 1777, Louis XVI required that d’Éon declare a gender. Rumors about d’Éon’s gender had already begun to circulate, with some claiming he bought and dressed in woman’s clothes and others speculating that he was a woman who had disguised her gender to join the army—several such instances had been recorded. In some versions of the story, it was d’Éon who demanded recognition as a woman as part of the settlement, eventually negotiating with the King to include a large sum with with to purchase a new wardrobe of women’s clothes.

In any case, at this point d’Éon began her public life as a woman. She said she had been born a girl but raised as a boy for purposes of gaining an inheritance from her father’s in-laws. She dressed lavishly at an official coming-out party at the French court.

Returning to Britain in 1785, d’Éon became a celebrity, her notoriety drawing crowds to fencing demonstrations in which she faced her opponents wearing (as in the portrait above), an elegant black dress and her Croix de St Louis. Although public debate continued regarding her gender, she was in large part recognized, accepted, and praised as a model example of her sex. She is mentioned in Mary Wollstonecraft’s Vindication of the Rights of Woman as one of many women “who, from having received a masculine education, have acquired courage and resolution.”

Her life ended sadly. Her French army pension ended with the French Revolution, and she was forced to sell off her possessions. She was wounded in a fencing tournament in 1796 and spent five months in a debtors’ prison. She died in poverty in 1810 at the age of 81.

The 1792 portrait is a copy by Thomas Stewart of an original by Jean-Laurent Mosnier.