Les Hommes Mystérieux ("The Mysterious Men") are the French equivalent of the League of Extraordinary Gentlemen, similarly composed of "questionable" or criminal individuals which the French Government granted them amnesty.
The French Government while critical of the British for employing many known rogues to their League ended up doing likewise.
The group was created by the French government sometime in 1909 in response to unconfirmed reports of a German conspiracy intended to bring war into Europe. Also, the group was further served as a countermeasure towards the English League. Mystérieux was lead by Jean Robur and his adjutant Arsène Lupin the Gentleman Thief, and includes the French superhero Nyctalope, criminal mastermind and terrorist Fantômas, and albino Monsieur Zenith.
Mystérieux was manipulated into fighting the English League by their German counterpart Die Zwielichthelden in which both groups believed that their respective counterparts are plotting to create the European war as foreseen from their respective intelligence. Both groups came into conflict from February 13th to March 14th, 1913 in which the League initially attempted to board Robur's airship by balloon and its captain retaliated by easily shooting down with airborne artillery, and finally at the Paris Opera House where their battle ended when Fantômas remotely detonates a large cache of explosives sequestered in the former lair of the Phantom of the Opera, collapsing a portion of the above opera house. In the aftermath, some 200 casualties were afflicted from the explosion and Les Hommes Mystérieux whereabouts remained unknown. It was presume that Mystérieux soon learned that the fight was setup by the "Twilight Heroes".
By the start of World War I, Les Hommes Mystérieux participated in the conflict in which Robur was killed at the Battle of Somme when his airship was shot down. After the war Les Hommes Mystérieux supposedly disbanded.