Charles-Geneviève-Louis-Auguste-André-Timothée d'Éon de Beaumont (1728 – 1810), usually known as the Chevalier d'Éon, was a famous French aristocrat, transvestite, diplomat, spy, dueler and a soldier in the French Army during the Seven Years' War.
In a time where dressing up was popular, d'Éon first dressed as a woman at a costume ball, aided by his slight build. King Louis XV took notice of him, and realized that d'Éon's appearance of a beautiful woman would make him easy to deploy as a spy. He was soon sent on a mission to Russia in 1756, equipped with a farthingale and a cascade wig. D'Éon listened at doors and stole documents with great dexterity. For this, Louis decorated him with the Order of Saint Louis.
After 49 years of dressing as a man on most occassions, d'Éon took to appearing publicly as a woman in 1777, sparking a debate on gender. When the Bastille was stormed in July 1789, he wrote to the National Assembly and offered to lead a division of female soldiers. However, this offer was rejected by the Assembly.
D'Éon was known for being a skilled swordsman, and frequently challenged fencers to friendly duels, betting they could not defeat a woman. This practice proved to be profitable for him. Sometime during the French Revolution, he contacted the Assassin Arno Dorian.
Upon meeting him, d'Éon told him not to be confused by his appearance. He then told Arno that he knew of his allegiance and that he needed his help. To prove that he was capable for the job, d'Éon asked the Assassin to challenge several swordsman to duels and defeat them. After Arno returned triumphant, d'Éon challenged him to a duel as a final test. After the Assassin won the duel, the latter congatulated him on being the best swordsman.
D'Éon later requested Arno's help in investigating the Crimson Rose, suggesting he help the man so he could be allowed into the Crimson League. Upon his discovery that the league's members were all Templars, d'Éon quickly alerted Arno to this fact, following which the Crimson Rose was assassinated.