Judex (whose name is Latin for "judge") is a mysterious avenger who dresses in black and wears a slouch hat and cloak.

[1] Louis Feuillade had already made two earlier serials, Fantômas (1913) and Les Vampires (1915), which were popular with audiences, but drew criticism for glorifying criminals.

After his father committed suicide as a result of being ruined by the villainous banker Favraux, Jacques de Trémeuse adopted the guise of Judex and assembled an organization of ex-criminals and circus people to bring down Favraux and his lethal mistress Marie Verdier.

In the subterranean passages beneath a ruined castle Judex had a base outfitted with technological gadgets.

He also had a secret identity: "Judex" (the Latin word for judge) was merely a nom de guerre he had adopted in his quest for revenge.

In 2013, Black Coat Press published a new screenplay by Robert L. Robinson, Jr., of a new adaptation of the Judex character.

[7] As an homage, writer Matt Fraction featured Judex as a member of a team of European superheroes of the early 20th century, in a 2012 issue of The Defenders.