Ferdinand Walsin Esterhazy (1847-1923). French military officer from 1870 to 1898. Spy for the German Empire, he was the author of the acts of treason for which Alfred Dreyfus was condemned. On 10 January 1898, he was tried before a military court. A court martial session. The court unanimously acquitted him. Engraving by Matute. La Ilustracion Espanola y Americana, 1898. (Photo by: Prisma/Universal Images Group via Getty Images)