Les Hommes Mystérieux ("The Mysterious Men") are the French equivalent of the League of Extraordinary Gentlemen, similarly composed of "questionable" or criminal individuals to whom the French government granted amnesty in order to protect France from extranormal threats.
The French government was made aware of the British League's existence in 1898. As early as 1901 the French had been discussing the formation of its own team, but was hesitant to recruit notorious rogues as the British had done. However, the French government ultimately saw no choice but to grant amnesty to several criminals, forming Les Hommes Mystérieux in 1909 in response to unconfirmed reports of a German conspiracy to launch a continent-wide war. (The group further served as a countermeasure against the English League.) Les Hommes Mystérieux were led by aeronaut and sky-pirate Jean Robur and his adjutant Arsène Lupin the Gentleman Thief, and included the criminal masterminds Fantômas and Monsieur Zenith, and the superhuman Nyctalope, a comparatively upstanding figure.
Les Mystérieux were manipulated into fighting the English League by their German counterpart Die Zwielichthelden, who convinced both groups that their respective counterparts were plotting to trigger a European war predicted by their respective intelligence agencies. Both groups battled during the period from February 13th to March 14th, 1913. The League initially attempted to board Robur's airship by balloon, but Robur easily shot them down with airborne artillery. The final confrontation between the British and French teams took place at the Paris Opera House. The battle ended when Fantômas remotely detonated a large cache of explosives cached in the former lair of the Phantom of the Opera, collapsing a portion of the building. The explosion caused some 200 deaths and Les Hommes Mystérieux went missing. It was presumed that Les Mystérieux soon learned that the fight was setup by the "Twilight Heroes".
Les Hommes Mystérieux participated in World War I. Robur was killed at the Battle of Somme when his airship was shot down. After the war Les Hommes Mystérieux apparently disbanded.