Paris, Lambert, 1779, 247+(1)pp. with engraved portrait frontispiece, later half linen binding, edges frayed, armorial bookplates of Mr. J. Havelaar and F. Koch Jr., Charles-Geneviève-Louis-Auguste-André-Timothée d'Éon de Beaumont or Charlotte-Geneviève-Louise-Augusta-Andréa-Timothéa d'Éon de Beaumont (5 October 1728 – 21 May 1810), usually known as the Chevalier d'Éon or the Chevalière d'Éon, was a French diplomat, spy, and soldier. D'Éon fought in the Seven Years' War, and spied for France while in Russia and England. D'Éon had androgynous physical characteristics and natural abilities as a mimic and a spy. D'Éon appeared publicly as a man and pursued masculine occupations for 49 years, although during that time, d'Éon successfully infiltrated the court of Empress Elizabeth of Russia by presenting as a woman. Starting in 1777, d'Éon lived as a woman. Doctors who examined d'Éon's body after death discovered ‘male organs in every respect perfectly formed’, but also feminine characteristics.Despite the fact that d'Éon habitually wore a dragoon's uniform, rumours circulated in London that d'Éon was actually a woman. A betting pool was started on the London Stock Exchange about d'Éon's true sex. D'Éon was invited to join, but declined.Some modern scholars have interpreted d'Éon as transgender.