Charles Marie Ferdinand Walsin Esterhazy was an officer in the French Army from 1870 to 1898. He gained notoriety as a spy for the German Empire and the actual perpetrator of the act of treason of which Captain Alfred Dreyfus was wrongfully accused and convicted in 1894.

Alfred Dreyfus was a French artillery officer of Jewish ancestry from Alsace whose trial and conviction in 1894 on charges of treason became one of the most polarizing political dramas in modern French history. The incident has gone down in history as the Dreyfus affair, the reverberations from which were felt throughout Europe. It ultimately ended with Dreyfus' complete exoneration.