The Legio Crucius ("Warmongers") is a Loyalist Titan Legion of the Collegia Titanica, one of the military arms of the Adeptus Mechanicus. There is very little information in Imperial records about this Titan Legion, though it is known to have been founded before the Great Crusade, most likely in the Age of Strife.
This Titan Legion has its great Perceptory and base of operations at Ryza, a major Forge World within the Segmentum Ultima. Ryza is renowned for the manufacture of Plasma Reactor and magnetic containment field technology. The arts and sophistication of this Forge World is claimed by some to be second only to that of Mars itself.
It is then unsurprising that the Legio Crucius, whose associations with Ryza are said to predate the Great Crusade, is renowned as one of the most well-equipped Titan Legions in Imperial service, and sufficient in number to provide garrison forces for several smaller outlying Forge Worlds and Adeptus Mechanicus outposts whose Magi maintain fealty or alliance to Ryza and its masters.
At some point in its history, Ryza was unsuccessfully invaded by Ork WAAAGH! Grax, and the Greenskins have continued to threaten this vital Forge World in the 41st Millennium, mounting two more invasions -- the latter of which is still ongoing.
As the green tide sweeps over Ryza, once more the god machines of the Legio Crucius walk to protect their homeworld, supported by Astra Militarum regiments sent to aid the world and by entire armies of Leman Russ Executioner tanks driven straight from the factories into the maelstrom. The mighty weapons of the Adeptus Mechanicus light the horizon with their fury, and yet still the Orks advance.
- Battle of Molech (009.M31) - Molech was a Knight World ruled over by House Devine ever since the Emperor Himself led an expedition to bring it into the fledgling Imperium and left a significant garrison there. The planet thrived under the rule of Devine, the populace of its capital city of Lupercalia never knowing the true reason why the Emperor had taken it upon Himself to lead the force that claimed it. Unfortunately for the citizens of Molech, the Traitor Horus knew exactly what lay beneath the city that had been named in his honour -- a Warp Gate which, it was said, had allowed the Emperor to convene with the Ruinous Powers themselves. When Loyalist forces became aware of the Traitor fleet's approach, they mustered at Molech. As well as a trio of Titan Legions -- the Legio Gryphonicus, Legio Crucius, and Legio Fortidus -- there were elements of each of the Imperium's fighting forces, including nearly a dozen Knight Houses which owed fealty to Devine. The Traitor force was equally impressive, featuring no fewer than four Titan Legions: the Legio Vulpa, Legio Interfector, Legio Vulcanum I, and the infamous Legio Mortis. As the Warmaster unleashed a massive coordinated assault, the planet's defenders were thrown into disarray when the Plasma Reactor of an Imperator-class Titan, Paragon of Terra, was destroyed. Thousands of Loyalists were immolated in a blinding flash as a miniature sun erupted from the Titan's core to leave a smoking crater half a Terran mile wide. In the wake of the catastrophic blast, the spearhead of Traitor Titans marched through the gap in the Imperial lines. At the height of the battle, House Devine revealed its true allegiance to the Warmaster, its treachery unveiled at a pivotal moment, heralding a slaughter from which only a handful of Loyalists escaped. Caught between the treacherous Knights of House Devine and Horus' rampant forces, the shattered remnants of Molech's defenders were slaughtered without mercy. They were totally defeated, so brutally that only one in a hundred of the troops of the Imperial Army survived the campaign. After his passage through the portal into the Realm of Chaos, Horus won the full blessing of the Ruinous Powers as their champion. His drive on Terra seemed unstoppable.
- Defence of Kado (Unknown Date.M41) - Titans of the Legio Crucius are known to have participated in the defence of the Hive World of Kado from the predations of a massive daemonic incursion. The god machines of the Legion suffered grave losses in the defence of a certain hive city, the name of which is now lost in Imperial records. As the Titans fired upon the advancing hordes of Chaos, felling hundreds upon hundreds of daemons and Heretics, a large force of Slaaneshi Daemon Knights infiltrated the hive city's massive subterranean transportation network. As the battle raged above them, the Chaos walkers sped through the dimly lit tunnels and corridors, quickly obliterating any resistance they encountered. On the second day of the hive city's siege the Daemon Knights emerged from beneath the ground and burst into the main streets and arcades of the city, finding themselves behind the Titans of the Legio Crucius, and within firing distance. With a single massed salvo from the Daemon Knights' Thermal Lances, nearly the entire Loyalist Titan battlegroup was destroyed, the august forms of the Titans turned into molten slag. Amongst the victims of this attack was the colossal Praeco Deictus, an Imperator-class Titan which had survived the grim days of the Horus Heresy and brought victory to the Imperium on over a thousand worlds.
- The Badab War (912-913.M41) - The Chapter Master of the Astral Claws, Lufgt Huron, the "Tyrant of Badab," sought to have the Badab Sector secede from the Imperium of Man in protest against the Imperium's continued attempts to use the resources of the Badab Sector outside the region rather than dedicating them fully to the defeat of the Forces of Chaos and xenos threats that emerged constantly in the Maelstrom Zone. This major rebellion involved several Space Marine Chapters who turned Renegade and sided with the Tyrant in his mad cause. The world of Angstrom was a highly militant minor Forge World containing a significantly independent Adeptus Mechanicus presence situated at the edge of the Maelstrom Zone, and by this web of kinship the Legio Crucius became involved in the Badab War's savage closing battles. The Legio Crucius forces deployed to the siege of Badab Primaris itself, comprised of three full maniples of Titans, some fifteen war machines in all, commanded by the Warlord-class Titan Hell's Daughter and the High Princeps Cadmon Krom. The Titans' principal task in the battle was to smash heavy defence points in Badab Primaris' hive cities and industrial zones and crush major pockets of resistance where encountered, a mission they undertook with great relish, fully living up to their Legion's long-standing reputation as savage city-breakers and world burners. The Legio Crucius accounted for untold casualties and devastated the remaining Secessionist heavy armoured forces. The Legion suffered only three losses during the engagement despite the heavy resistance they encountered, and managed to recover all but one of their wrecked Titans in the anarchic retreat from the planet.
- Defence of Ryza (Unknown Date.M41) - At some point in its history, Ryza was unsuccessfully invaded by Ork WAAAGH! Grax, and the Greenskins have continued to threaten this vital Forge World in the 41st Millenium, including the current assault upon Ryza. Foreshadowing what would happen if Ryza were to fall, the factory world of Proctus Prime has been conquered and its human populace enslaved to produce weapons for the Orks. After a series of battles, the Battlewagon battalions have overtaken the world of Hybernia and its invaluable Promethium mines. Many other worlds in the sector surrounding Ryza have also fallen to the Orks during their drive on the Forge World. As the green tide swept over Ryza, once more the god machines of the Legio Crucius moved to protect their homeworld, supported by Astra Militarum regiments sent to the aid of the world and entire armies of Leman Russ Executioner tanks taken straight from the world's manufactoria to the battlefield. The mighty weapons of the Adeptus Mechanicus lit the horizon with their fury, and yet still the Orks advanced. The fate of Ryza hung in the balance and the outcome of this campaign is as yet unknown.
- Third War for Armageddon (998.M41) - Ork Warlord Ghazghkull Mag Uruk Thraka launched a second and even more massive Ork WAAAGH! to conquer the Imperial world of Armageddon in 998.M41. During a ten-day battle that raged over the Diabolus manufactorum complex and proved to be one of the most fierce of the Third War for Armageddon, Titans from the Legio Crucius engaged the Gargants of the Warlords Burzuruk and Skarfang. Six Titans and eight Gargants were utterly destroyed in the fighting and many others needed solar months of repairs before they could fight again. The Diabolus complex was wrecked during the battle, its foundries and machine shops blasted apart or crushed underfoot by giant fighting machines.
- Paragon of Terra (Imperator-class Titan) - The Paragon of Terra was an Imperator-class Titan of the Legio Crucius under the command of the Princeps Magnus Etana Kalonice, and served as the key element of the Loyalists' defence during the Battle of Molech. The Paragon of Terra was destroyed by treacherous Renegade Knights of House Devine.
- Astramos Mortis Æternem - A Reaver-class Titan of the Legio Crucius which took part in the Badab War.
- Primus Secutar - A Reaver-class Titan of the Legio Crucius which took part in the Badab War.
- Hell's Daughter - A Warlord-class Titan commanded by High Princeps Cadmon Krom during the final Loyalist assault on Badab Primaris during the Badab War.
- Black Strider - A Warhound-class Titan of the Legio Crucius which took part in the Badab War.
- Blood of Caldos - A Warhound-class Titan of the Legio Crucius which took part in the Badab War.
- Wolfshead - A Warhound-class Titan of the Legio Crucius which took part in the Badab War.
- Praeco Deictus - An Imperator-class Titan which had survived the grim days of the Horus Heresy and had won countless victories on thousands of worlds for the Imperium. The Praeco Deictus was destroyed, along with other Titans of the Legio Crucius, defending the Hive World of Kado from the Forces of Chaos. During the fighting, a hundred Slaanesh Hell-Knights infiltrated the main Hive City and emerged to attack the Imperator Titan from the rear where it was most vulnerable, turning it into a pile of molten slag.
- Cadmon Krom - High Princeps of the Legio Crucius during the Badab War. He personally led the final attack of three full maniples of Titans, comprised of 15 war machines during the Imperial siege of Badab Primaris.
The colours of the Legio Crucius are black and white.
The Legion badge of the Legio Crucius is a black gauntlet curled into a fist, superimposed over an Adeptus Mechanicus gear. A white letter 'T' representing the identifier for the Collegia Titanica is located on the back of the gauntlet.
- Adeptus Titanicus - The Horus Heresy: Rulebook (Specialty Game), pg. 15
- Imperial Armour Volume One, pg. 8
- Imperial Armour Volume Ten - The Badab War - Part Two, pp. 43, 45, 49-51
- White Dwarf 190 (UK), "Epic: Slaanesh War Machines", pg. 29
- White Dwarf 142 (UK), pg. 34
- Warhammer 40,000 Rulebook (6th Edition), pg. 202
- Vengeful Spirit (Novel) by Graham McNeill, Ch. 13
- Third War for Armageddon Worldwide Campaign
- Warhammer Community - Doom of Molech: What’s In the Book