Author, envoy, soldier, spy, the Chevalière d'Eon spent half her life in France, presenting as a man, and the other half in London, presenting as a woman. D'Eon fought in battle, negotiated peace treaties and leaked state secrets, narrowly escaping the Bastille. Defying royal authority and gender norms alike, in the 1770s she became one of Europe's first celebrities. Drawing on a raft of unpublished life writings, Conlin reveals for the first time how d'Eon used a range of genres and voices to tell the story of her transition. He provides a comprehensive account of d'Eon's place in trans history, Anglo-French relations, and celebrity culture. Rather than a postmodern masquerade of gender play, Conlin argues that d'Eon's multiple avatars offer us a new way of telling trans lives.