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.

Legion HistoryEdit

At the outset of the Horus Heresy, Warmaster Horus sent Regulus (an Adeptus Mechanicus representative who had already thrown in his lot with the Traitors) to Mars to secure the tentative support of the Fabricator-General of the Adeptus Mechanicus, Kelbor-Hal, for Horus' rebellion. Regulus convinced the Fabricator-General of the Warmaster's resolve to support increased autonomy for the Mechanicus against the autocratic rule of the Emperor of Mankind. As a show of his appreciation for the Fabricator-General's support, Horus provided information to Kelbor-Hal that allowed the Tech-Priest to open a repository of forbidden knowledge known as the Vaults of Moravec, which the Emperor had ordered sealed.

Loyalist Titan2

A Loyalist Titan

When this repository was reopened, there was all manner of forbidden arcane knowledge and weaponry that had obviously been tainted by the corrupting influence of Chaos stored within. Soon the corruption spread throughout the forges and temples across the Red Planet as scrap code -- Chaos-contaminated digital source code that was infected with an arcane computer virus -- infested the logi-stacks and Cogitator (computer) archives of the Adeptus Mechanicus, causing literal Chaos to emerge in any Cogitator system that was networked to one of its infected counterparts. The Fabricator General and his Dark Mechanicum allies used this disruption to marshal the strength of their forces, intent on bringing the rule of Mars firmly under their control. Infected by this vicious scrap code, the Titans of Legio Fortidus and Legio Agravides met their end when their reactors went critical and exploded, destroying their fortresses and eliminating these once-proud Titan Legions from the roster of Loyalist forces. In later years, this night would become known in Mechanicus legends as the Death of Innocence.

Notable CampaignsEdit

None listed in current Imperial records.

Notable TitansEdit

None listed in current Imperial records.

Notable PersonnelEdit

None listed in current Imperial records.

Legion AppearanceEdit

Legion ColoursEdit

The colours of this Titan Legion are not listed in current Imperial records.

Legion BadgeEdit

The Legion badge of the Legio Fortidus is not listed in current Imperial records.


  • Mechanicum (Novel) by Graham McNeill