L'homme protée (French for protean man) was a term used for stage female impersonators cum quick-change artists from the turn of the 20th century to the mid 1920s,
Louis Vernassier, 1906. See temposenzatempo.
A "Vernassier, Louis" was killed in action at Saint-Jean-de-Bassel on 20 August 1914 (only three weeks into WWI) - this may be the same person.
Lilly-Armand Maurice, 1908
Both these photographs are in the Digital Transgender Archive, and are taken from the James Gardiner 20th Century Drag Postcards collection at the Wellcome Library.