The Legio Fortidus was a Loyalist Titan Legion of the Collegia Titanica, the most powerful military arms of the Adeptus Mechanicus. Founded well before the Age of the Imperium, quite possibly during the Age of Strife, on the Mechanicum’s sacred world of Mars, very little information is available on this Titan Legion. The Legio Fortidus is generally believed to have perished in the opening days of the Schism of Mars, if indeed or to what extent the Legion survived the Horus Heresy or was rebuilt during the Great Scouring remains unknown.