The Legio Invicta 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's founding, though it is known that it was raised before the Age of the Imperium began, during the Age of Strife. This Titan Legion is known to have functioned for nearly twelve standard millenia. The Legio Invicta is based on the Forge World of Proximus, and all of its war engines are mentioned to be exclusively of the Proximus Pattern.
- War of Lochrisus (412.M35) - The Imperial Warmaster Gallivant ordered the Legio Invicta to the Shackropal System to stem a swarming by the xenos known as the Lethids. The Legio Invicta 's commander refused, claiming it would be a waste of his war engines' time and materiel. The Shakropal star went supernova the next year, and the Lethids were immolated without need for the Titan Legion's intervention.
- Persecution of Warmaster Hengis (741.M41) - Once again the Legio refused an Imperial edict when their Princeps Maximus was forced to disobey the clinically insane Imperial Warmaster Hengis on Talphus VII. The Legio Invicta was ordered, eventually, to annihilate the insane Warmaster and the forces that followed him. This Imperial action against one of the Emperor's own was kept quiet and all records of it were kept sequestered within the Imperial archives by order of the Inquisition.
- Beltran Cluster Campaign (771-778.M41) - The Beltran Cluster Campaign was a seven-standard-year-long campaign executed against the Eldar in the Beltran Cluster. The campaign was a success but the Legio Invicta suffered the loss of 8 war engines to the subtle, graceful Titans of the Eldar.
- Defence of Orestes (779.M41) - The homeworld of the Legio Tempestus, the Forge World of Orestes, was invaded by a large force of Traitor Titans during the Sabbat Worlds Crusade, to which the world had contributed much war materiel and for which it was a vital source of supply by virtue of its close proximity to the theatre. The Crusade Warmaster's constant requests for materiel and the support of the Legio Tempestus had drained the world of resources and left it weak -- rendering it a perfect target for Archon Urlock Gaur, the commander of the Forces of Chaos in the sector. The Dark Mechanicus in the Archenemy's service blinded the planet's sensors and allowed bulk landers to set down in the Astrobleme region and disgorge their engines of war. As a result of the Forge World's having met the Warmaster's demands, the Legio Tempestus had been left with only a token force of twenty-two Titans to defend its homeworld -- nowhere near enough to face an enemy Titan force seven times this size. The Legio Tempestus was unable to cover ground and found itself outnumbered, outgunned and outmaneuvered at nearly every turn, losing eight Titans in the first days of fighting. Orestes escaped swift and inevitable destruction only thanks to the arrival of the Legio Invicta, which was passing near the planet on its way to the Sabbat front. The bulk of the Legio Invicta landed in Orestes Principal, and after three days of preparation, it moved out into the Jeromihah Subsidiary and adjacent areas, engaging the forces of the Archenemy on Orestes for the first time. The Legion's efforts bore fruit, as its forces scored many Titan kills with few losses of their own, eventually causing the Traitors to converge on the ruins of Hive Argentum in hopes of drawing the two Imperial Titan Legions to full-scale battle -- a challenge which the Legio Invicta Princeps Maximus Pietor Gearhart, against the advice of a number of his senior Princeps, accepted, also wishing to wipe out the enemy. In the meantime, the Orestean Analyticae Department, at the behest of the Legio Invicta, had been reviewing pict scans of Traitor war engines in order to discover their original identities as Adeptus Mechanicus Titans, and in extension any weaknesses and construction flaws they might exhibit. To this end, the Orestean Magi opened sequestered archives, containing materials pertaining to the Horus Heresy and the times before the founding of the Imperium. Amongst these, a document proving beyond the shadow of a doubt that the Emperor of Mankind was not the Omnissiah was discovered, and leaked out of the Analyticae offices. Such revelation confirmed the beliefs of the Mechanicus of Orestes and many other Forge Worlds, and caused outrage amongst the Imperial populace of the Forge World. In the ensuing chaos, a triumvirate of conspirators -- Legio Tempestus Executor Fetial Enhort, Master of the Archives Tolemy, and Master of the Analyticae Egan -- moved in to seize power in the forge city. They had known about these revelations for several years, and were merely using the war as an excuse to open the archives and publish them. This news reached the Titans in the field as they were closing in on Hive Argentum, and caused a rift between the two Legions, for the Legio Invicta did not share the beliefs of their allies and continued to venerate the Emperor as the Omnissiah. Despite this theological strife, they continued their operations, and although they suffered some losses, they ultimately achieved a crushing victory, obliterating nearly the entire force positioned against them. Following the battle, the Legio Invicta Princeps Maximus Gearhart wished to move the forces of the two Legions back to the forge city to restore order, but was confronted by the Legio Tempestus. Despite being outnumbered by a four-to-one margin, the Legion of Orestes' acting commander issued Gearhart an ultimatum, telling him to stand with the Legio Tempestus or against it. Legio Tempestus war engines proceeded to acquire target locks on Legio Invicta machines. Bloodletting between the two Titan Legions was perhaps only averted by a miracle -- during the course of the war a large storm which blocked orbital scans emerged over the Western Prospection. This weather anomaly turned out to not be natural, but generated by a climate tower erected by the forces of the Archenemy in order to conceal a sizable part of its forces. This tower was discovered by a stray unit of the Imperial Guard which succeeded in destroying it. The emergence of this new threat posed by a previously hidden Traitor Titan battlegroup which outnumbered the remaining operational Imperial Titans caused the two Legions to set aside their religious differences and move to face it. By virtue of the skills of the Titan Princeps, the Loyalist Titan Legions succeeded in destroying this threat as well, and by the time the fighting finished, the danger of schism within the Mechanicus was already over -- Tolemy revealed to Enhort and their associate, Egan, that he had manipulated the data to produce the outcome he had desired. Enhort was infuriated, stating that altered data undermined their position and the validity of their theological claims, and attempted to contact Gearhart to acquiesce to his demands. Tolemy attempted to strangle the Executor, but was stopped by Egan, who killed him with a weapon brought to the meeting in secret -- and subsequently committed suicide, struck with grief over the fabrication that he had unwittingly assisted. Following this event, Enhort submitted to Gearhart. Orestes had been delivered from the rampaging Traitor Titans and, alongside the broader Imperium, from the danger of a terrible religious schism.
- Ajax Excelsus - Titan of an unknown class and the war engine of Princeps Levin during the defence of Orestes.
- Divinitus Monstrum - Warlord-class Titan and war engine of First Princeps Bohrman during the defence of Orestes.
- Dominatus Victrix - The Warlord-class Titan Dominatus Victrix was commanded by Princeps Skaugen at the time of the Beltran Cluster Campaign, during which the Titan was damaged and its Princeps suffered injuries that ultimately proved lethal. The machine, however, was required to take part in the defence of Orestes, and to this end the Orestean Magi had agreed to repair it, and the Legio Tempestus offerred one of its Princeps -- Guido Prinzhorn -- to allow it to operate.
- Invictus Antagonistes - Warlord-class Titan and the war engine of Princeps Maximus Pietor Gearhart.
- Lupus Lux - Warhound-class Titan and war engine of Princeps Leyden Krugmal.
- Martial Nox - Warhound-class Titan and war engine of Princeps Talentine. The Martial Nox was destroyed in the drive on Hive Argentum as a result of an ambush set up by Traitor Titans.
- Morbius Sire - Warhound-class Titan and war engine of Princeps Maximillian Orfuls.
- Philopos Manix - Reaver-class Titan and war engine of Princeps Stent Racine.
- Sicarian Faero - Warlord-class Titan and war engine of Princeps Vancent Kung.
- Pietor Gearhart - Pietor Gearhart was the Princeps Maximus of the Legio Invicta and the commander of the Warlord-class Titan Invictus Antagonistes during the defence of Orestes. Several centuries of skillfully applied warfare, along with his own temperament, had earned him the name "Red Fury". At the time of the Sabbat Worlds Crusade and the defence of Orestes he had already been the Legion's Princeps Maximus for nearly three Terran centuries, and due to the long exposure to his Titan's mindscape was struggling to maintain his sanity while in the embrace of his Titan's Machine Spirit. At times during the defence of Orestes, he was haunted by hallucinated phantoms of his former crewmen and masters, and was struggling to remember the names of people he knew -- unconsciously substituting for them with those of his apparitions. Despite these drawbacks, he led his Legion to the successful conclusion of the Orestes Campaign. He did not shun risk, trusting that the Red Fury that gave him his name would deliver him as it always had. For this reason, when the Traitor Titans began to converge on the ruins of Hive Argentum during the defence of Orestes, Gearhart, against the advice of some of his senior Princeps, decided to battle the enemy force, hoping to wipe it out entirely -- though such a fate might have been that of his own Titan Legion. Gearhart's assertion proved correct, as his forces won the battle. After the fighting had ended, he wished to move the forces of the two Legions back to the forge city to restore order, but was confronted by the Legio Tempestus. Despite being outnumbered by a four-to-one margin, the Legion of Orestes' acting commander issued Gearhart an ultimatum, telling him to stand with the Legio Tempestus or against it. Gearhart's unflinching and unyielding attitude may have very nearly sparked a civil war within the Mechanicus. Bloodletting between the two Legions was only averted by the emergence of a new threat posed by a previously hidden Traitor Titan battlegroup. Gearhart led the two Legions to victory in the final battle of the war on Orestes, and soon afterwards, the danger of a religious schism was over. Immediately following the campaign, Gearhart is shown as still being in command of the Legion. His ultimate fate, and whether he succumbed to his insanity, is unknown.
- Bohrman - Bohrman was a First Princeps of the Legio Invicta during the defence of Orestes and the commander of the Warlord-class Titan Divinitus Monstrum. He was Gearhart's second in command, and was being prepared to take the position of Princeps Maximus when Gearhart finally loses his ability to lead the Legion.
- Vancent Kung - Vancent Kung was the Princeps of the Warlord-class Titan Sicarian Faero during the defence of Orestes. He was the commander of one of the Titan battlegroups assaulting Hive Argentum, and was tasked by Princeps Maximus Gearhart to destroy the Traitor Imperator-class Titan Augmenautus Rex. Kung linked his MIU (Mind Impulse Unit) with those of Titans from three battlegroups to take down the Traitor Imperator-class Titan with an assault coordinated by a single mind. Such a measure, although forbidden, was required as the Augmenautus Rex 's Void Shields were so potent that they would have withstood a more dispersed assault. Kung had controlled a large number of Titans for only a few moments during which he succeeded in disabling the Chaos Titan, but this effort weakened him considerably.
- Levin - Levin was the Princeps of the Titan Ajax Excelsus. He commanded a second front of war engines which struck of the Gynex Sub-hive on Orestes to support the attack on Hive Argentum from the south. His forces assisted in bringing down the Traitor Imperator-class Titan, Augmenautus Rex.
- Stent Racine - Stent Racine was the Princeps of the Reaver-class Titan Philopos Manix during the defence of Orestes.
- Maximillian Orfuls - Maximillian Orfuls was the Princeps of the Warhound-class Titan Morbius Sire during the defence of Orestes. He was noted as being a senior war engine pilot, and is credited with drawing first blood for the Legio Invicta on the surface of Orestes.
- Leyden Krugmal - Leyden Krugmal was the Princeps of the Warhound-class Titan Lupus Lux during the defence of Orestes.
- Talentine - Talentine was the Princeps of Warhound-class Titan Martial Nox during the defence of Orestes. Talentine died during the drive on Hive Argentum as a result of an ambush set up by Traitor Titans.
- Skaugen - Skaugen was the Princeps of the Warlord-class Titan Dominatus Victrix during the Beltran Cluster Campaign. While fighting the graceful Eldar Titans his war engine sustained damage and he himself was severely injured. As a result of this, Skaugen was put in stasis in hopes of preserving his life, however he died shortly after the Legio Invicta arrived on Orestes.
- Zane Tarses - Zane Tarses was a Moderatus of the Warlord-class Titan Dominatus Victrix during the Beltran Cluster Campaign and the defence of Orestes. After his Princeps had died in Orestean facilities, Tarses, blinded by grief and rage at the efforts that seemed to him to be only diminishing his master's faculties, murdered the Magos Organos that tended to Skaugen. While such a crime would normally have seen Tarses executed, the circumstances the Legio Invicta was in led him to be temporarily spared. The Legion faced numerous foes and needed all of its available engines. The Dominatus Victrix would be repaired and a new Princeps -- Guido Prinzhorn -- would be provided for the war engine by the Legio Tempestus. Tarses knew the machine, and it knew him. He was required to ease the new Princeps into enmeshing with the war engine's Machine Spirit to make sure that the Titan operated at full capacity. To this end, Princeps Maximus Gearhart ordered Tarses' crime overlooked and the charges suspended until the conflict on Orestes was over. Like all Proximus Pattern Warlord-class Titans, the Dominatus Victrix required a full-immersion amniotic interface to operate it, and this Prinzhorn could provide. Despite being a young Princeps, and one who had never seen actual combat but only simulations, Prinzhorn was interred in an amniotic tank. Prinzhorn was afraid of his first real command, and was predictably less able than a more experienced Titan officer. Prinzhorn was aided in his charge by Tarses, even though he was initially reluctant to accept this help. Following the battle for Hive Argentum, after the publication of the revelations which allegedly proved the truth of the Orestean Heresy, Legio Invicta Princeps Maximus Pietor Gearhart wished to move the forces of the two Legions back to the forge city to restore order, but was confronted by the Legio Tempestus. Despite being outnumbered by a four-to-one margin, the Titan Legion of Orestes' acting commander issued Gearhart with an ultimatum, telling him to stand with the Legio Tempestus or against it. When Legio Tempestus war engines acquired target locks on the Legio Invicta 's Titans, Prinzhorn did the same, but was stopped by Tarses, who forced the Princeps to shut down his Titan at gunpoint. Bloodletting between the two Legions was only averted by the emergence of a new threat posed by a previously hidden Traitor Titan battlegroup. Prinzhorn and Tarses proceeded to take part in the final battle of the war on Orestes. Tarses' ultimate fate is unknown.
- Djared Crusius - Djared Crusius was an Executor Fetial, a diplomat, of the Legio Invicta during the defence of Orestes. He was present on Orestes during his Legion's transit from the Beltran Cluster to the Sabbat Worlds front, and negotiated the aid of the Legio Invicta with the Orestean Magi. During the campaign, he travelled behind the forces of the Legion in a guarded, armoured convoy, supporting them in any way he could -- serving as a liaison between the various units and entities, Imperial and Mechanicus alike, and monitoring the events in the entire theatre, providing all of this information to Princeps Maximus Gearhart.
- Sonne - Sonne was the Famulous of Executor Fetial Djared Crusius, apprenticed to one day hold this station himself. Sonne was most often found at the side of his master, though he was occasionally sent away on errands. Because of this, he was present, along with a Legio Invicta Skitarii escort, in the forge city of Orestes Principal during the coup d'etat which occurred after the publication of the revelations concerning the Emperor's supposed lack of divinity. Using his master's security codes, he was able to extract a witness of the Adept Seniorus' murder from the forge city and deliver him to Imperial authorities. The account of events delivered by this witness served to further and finally convince Gearhart to move against the forge, as he had all the proof he needed of the Orestean Heretics' duplicity.
- Lau - Lau was the Master of the Legio Invicta 's attached Skitarii forces during the defence of Orestes. Like all of the Mechanicus' Tech-Guard he was heavily augmented with cybernetic implants which were designed for combat. He commanded his troops personally and was often found fighting on the first line -- despite numerous admonitions from his Princeps Maximus. Lau claimed that doing so prevented him from ever becoming complacent about the lot of the Skitarii under his command, but Gearhart believed him to be simply addicted to the adrenal high of close combat.
- Kovenicus - Magos Navis Kovenicus of the Adeptus Mechanicus was the Master of the Legio Invicta fleet, in command of all of the Titan Legion's naval assets. When the reveletations concerning the Emperor's non-divinity were made public by the Orestean Heretics, Kovenicus, in correct anticipation of Gearhart's orders, placed his vessels in geo-synchronous orbit over the forge city of Orestes Principal to make ready for orbital bombardment and the deployment of reserve troops, in preparation for the possible outbreak of a civil war between the forces of the Orestean Mechanicus and those of the Imperium.
The Legio Invicta's colours are red and gold.
The Legio Invicta's badge is not listed in current Imperial records.
A certain Lord Gearhart is mentioned to have been the Legio Invicta 's commander during the War of Lochrisus in 412.M35. It could not have been Princeps Maximus Pietor Gearhart, however, as he is actually mentioned to have become the Princeps of the Invictus Antagonistes in 466.M41, and the Legio Invicta 's Princeps Maximus in 496.M41, prior to that being only a Famulous and a Moderatus. This is most likely an error or simply a reference to another Lord Gearhart who once held the same position within the Legion.
Additionally, the Legion is said on a number of occasions (including one time when viewed by the Legio 's crewmen) to bear red and gold colours. However, it is also mentioned that the Legion's Titans are painted in crimson and brass, albeit only once, in a modeller's shop. For this reason, the red-and-gold scheme is accepted as the canon Legion colours until further evidence indicates otherwise.
- Titanicus (Novel) by Dan Abnett