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The Legio Tritonis ("Dark Tide") was the first Blackshield Legio, a Titan Legion that fought only for itself and neither for the Imperium of Man nor for the Traitors of Chaos during the Horus Heresy.

Hailing from the Forge World of Arachnus, during the middle years of the galaxy-wide civil war of the Horus Heresy, the planet and its two neighboring moons became engulfed in internecine conflict.

Seeking to overthrow their perceived oppressors, which happened to include both the Emperor and the Warmaster Horus, this conflict eventually resulted in the rebellious elements having uncontested control of both Arachnus and its moon Iktomia, though battle still raged on the other moon, Nizkara, led by the fierce resistance of a handful of Legio Venator Titans.

Arachnus declared itself an independent state and fought both Loyalist and Traitor alike during the Heresy. Originally formed from the secessionist faction of the Loyalist Legio Venator, Arachnus' newly founded Titan Legion renamed themselves the Legio Tritonis in homage to the three celestial bodies of their homne system -- Arachnus and its two moons, Iktomia and Nizkara.

Others would come to know them by another name, calling them "Dark Tide" for the widespread destruction they brought down upon any who opposed them before they were finally purged from Arachnus by a Loyalist assault led by their own kin of the Legio Venator.



Legio Tritonis Warlord Titan

Legio Tritonis colour scheme as displayed by the Warlord-class Titan Chainbreaker during the Horus Heresy.

The name of the Legio Tritonis is one few would commonly associate with the Forge World of Arachnus, for the nascent Titan Legion did not exist within any known records before the onset of the Horus Heresy and the seccession of Arachnus from the Imperium of Man.

Indeed, it is the Legio Venator that was first founded upon the distant Forge World during the Age of Strife as wardens against the gargantuan arachnid-like fauna that roamed the planet. The legacy of the Iron Spiders, to use the more common appellation of the Legio Venator, is integral to the foundation of the Legio Tritonis, for many of the former's princeps formed the core of the latter, loyal to Arachnus before any other.

The motivations behind the creation of the Legio Tritonis are complex and rooted in the desire of Arachnus to remain independent of distant rulers. When the Forge World was discovered by the Great Crusade, it heavily resisted integration with the Imperium, surrendering only after several standard years of warfare that left both sides bloodied.

Even after they were subjugated and brought into the Imperial fold, Arachnus appeared, at times, malcontent, working tirelessly to build a power base within the Belt of Iron and assert its influence within the wider Imperium.

At the forefront of such efforts was its attempts to increase its power in the Martian Parliament, with fleets dispatched from Arachnus seeking out undiscovered lesser Forge Worlds and offering them patronage in return for control of the newcomer's vote in the parliament of the ancient Mechanicum.

Furthermore, Arachnus proved adept at shielding its inner workings from outside interference, delaying tithe ships and concealing forge-fanes from Martian delegations. The Forge World's defiance was balanced by its securing of supply deals with the Emperor's own Legio Custodes; possessing skill in laser technology that proved second to none. Arachnus became indispensable in ensuring the Custodes had access to rare weapons technology, earning the Forge World political leeway in its dealings with other Imperial parties.

The Legio Venator also showed a measure of dissension during the Great Crusade, at least in those princeps left to watch over the domain of Arachnus. While the principal strength of the Titan Legion was dispatched to the forefront of the Great Crusade, and in doing so developed a firm belief in self-sacrifice and a devotion to the wider Imperium, the remaining god-engines remained closer to their home Forge World.

Such elements of the Legio Venator proved resistant to Imperial commands, lending aid to nearby beleaguered worlds at the behest of the Arachnus magi and ignoring any orders from external commanders.

The stark difference in ethos of those of the Legio Venator deployed across the expeditionary fleets and those remaining within the borders of Arachnus' holdings would eventually lead to an ideological split in the Titan Legion, with princeps from both elements publicly trading barbs on numerous occasions.

Matters only intensified when the principal strength of the Legio Venator was rotated back to Arachnus for repair and refit, with escalating tensions threatening bloodshed. Such an outcome was delayed, but not halted, by the outbreak of the Horus Heresy.

Horus Heresy[]

Legio Tritonis Warmaster Battle Titan

Legio Tritonis Warmaster Heavy Battle Titan Bellator Libertas during the Horus Heresy.

The ideological splits between the two disparate elements of the Legio Venator were to bring much strife to Arachnus. Like many Forge Worlds across the Belt of Iron, Arachnus kept its intentions and loyalties secretive during the opening years of the conflict. Political factions present on the Forge World called for Arachnus to join the war both for the Imperium and against it, while others demanded it seize the moment and establish a new order with the Forge World at its centre.

Matters came to a head when a cadre of senior princeps, who had served for solar decades within the Great Crusade, demanded Arachnus fulfil its duties to Imperium and Emperor or face dissent and rebellion at home. In response, several demi-legios of the Legio Venator were dispatched for the Ny'Drinah Sub-sector, ostensibly in support of the Imperial war effort in the region.

Given later events, it is clear such a move was intended to rid the Forge World of dissenting elements, the dispatched demi-legio made up primarily of those who held loyalty to the Imperium over their Forge World.

Shortly after Arachnus' apparent declaration of support for the Imperium, communications between the Forge World and other planets halted. Docking manifests indicate that voidships in the employ of the Warmaster Horus' fleets alighted at the Forge World during this time, with inventory records detailing shipments of plasma reactors, Titan-grade munitions and raw materials necessary for the construction of god-engines.

The nature of these shipments suggest the Warmaster believed he had secured the Forge World as his ally and worked to swell the size of those Legio Venator elements loyal to Arachnus.

In this, both the Imperium and the Warmaster were fooled. Having reaped the benefits of claiming allegiance to both sides, Arachnus broke its silence to announce its independence, declaring both the Emperor and the Warmaster as conquerors and murderers who deserved no respect from the Forge World and its people. A brief period of cleansing followed upon Arachnus, with Legio Venator princeps who refused to break their oaths with the Imperium set upon by maniples of Titans bearing altered colours and assembled under a new banner.

In acknowledgement of its new path, the secessionist elements of the Legio Venator rallied under a new name -- the Legio Tritonis, chosen in honour of their Forge World and its two moons, Iktomia and Nizkara. Though warfare between secessionist and Loyalists was to rage on Nizkara, the second moon of Arachnus, for the remainder of the Horus Heresy, the Legio Tritonis had secured the remainder of Arachnus' holdings and cemented its standing as a powerful independent state.

The newly appointed wardens of Arachnus were bequeathed two tasks. The first was the total extermination of the surviving elements of the Legio Venator, who were declared as Traitors to their heritage and their ancestral world. To this end, hunter maniples were assigned to the regions surrounding M'Khand, a secondary Forge-fortress appropriated as the primary base of operations for the Legio Venator in the Belt of Iron following the rebellion of Arachnus.

Though the princeps of the Legio Venator and the Legio Tritonis had once walked beneath the same banner, neither spared compassion for the other, and death and destruction was visited upon numerous worlds as both Titans Legions sought to eradicate the other.

The second task proved to be the expansion of Arachnus' holdings, the Forge World proving ill-content with its current borders. Legio Tritonis demi-legios were frequently reported on worlds bordering the Forge Empire of Arachnus, its god-engines descending upon lesser Forge Worlds who had, in the past, aligned themselves with Arachnus. Portrayed as emissaries for a prosperous new order, any who denied requests for subservience were greeted with fire and flame, populations slaughtered until the worlds bowed to Arachnus.

This wanton campaign of conquest and destruction soon earned the Legio Tritonis a new name, for survivors proclaimed that its godengines descended like a tide of darkness, snuffing out all hope.

The Legio Tritonis thrived during the Horus Heresy, using plundered resources in conjunction with god-engines captured through conflicts with the Legio Venator and other Titan Legions within the Belt of Iron to rapidly increase its numbers. Eventually, the Dark Tide was to face its reckoning when the Iron Spiders returned to Arachnus with the support of the Legio Atarus. The resulting conflict raged for several standard years and, upon its conclusion, Arachnus was once more brought to heel by the Imperium's war machine.

Official records state that all dissenting elements of Arachnus, including the Legio Tritonis, were exterminated to a person. Nevertheless, scattered reports appeared throughout the Heresy of god-engines bearing the colours of the Legio Tritonis, many standing sentinel over concealed Mechanicum enclaves within the Belt of Iron that proved hostile to diplomatic efforts and quick to relocate should efforts be made to conquer them.

Arachnus and the Legio Custodes[]

Given the barely concealed anti-Imperial sentiments of many amongst the ruling powers of Arachnus, it is ironic that much of the Forge World's prominence was built upon its role in supplying the Emperor's own Legio Custodes. Arachnus' expertise in laser technology soon saw them become a favoured supplier of the Custodes, with Arachnus Blaze Cannons and Arachnus Storm Cannons seeing frequent use on the heavier support elements of the Legio Custodes.

Alongside this, Arachnus gained further renown for the loyal service elements of the Legio Venator gave within the expeditionary fleets of the Great Crusade, with many of its princeps noted for heroism and self-sacrifice. Combined, these two factors were seen by many amongst the Imperium as evidence of a societal shift amongst the once fiercely-resistant people of Arachnus, with the Forge World slowly transitioning into firm subjects of the Imperium. As history proved, this assessment was woefully ignorant.

Notable Campaigns[]

  • Cataclysm of Iron (010-015.M31) - In the region of the galaxy home to many minor Forge Worlds known as the Belt of Iron, the Horus Heresy brought many long-held grudges to the surface. Realising how crucial the Forge Worlds in the area were to both sides in the conflict, both Traitors and Loyalists alike contended for control of the region during the battles of the Heresy.
    • Dark Tide (218.011.M31) - In the years following the events in the Isstvan System, the loyalty of the Forge Empire of Arachnus became suspect. Within the borders of Arachnus, two warring ideological sects fought a political battle that would determine the allegiance of the Forge Empire. Those that had spent solar decades serving in the Great Crusade held great respect for the Imperium and its values and advocated for standing against the Warmaster Horus in aid of the Emperor, while others claimed the unfolding civil conflict served as the perfect backdrop against which Arachnus could once more seize control of their own independence. This disagreement appeared settled following repeated expressions of concern from the wider Imperium, interlaced with implicit threats from the Imperial Household itself, that bade the Forge World resume shipments of aid and supplies to worlds both within the Belt of Iron and further afield. In answer, the rulers of Arachnus dispatched several fleets, and several dozen Legio Venator god-engines, to aid the Loyalist push into the Ny'Drinah Sub-sector. It fell to those who had served widely during the Great Crusade to lead the war efforts of the Legio Arachnus within the Belt of Iron, while other elements were given the task of guarding the borders of Arachnus. Close observation of deployment records show that the distribution of military strength outside the borders of the Forge Empire of Arachnus largely consisted of those who refused to support the idea of independence, placing them far removed from the Forge World. The first reports of conflict upon Arachnus itself came in the closing days of 010.M31, with data indicating the discharge of weapons fire within the principal Legio stronghold upon the Forge World. Having committed many of the dissenting elements of the Legio Venator to far-flung conflicts, the Titan Legion of Arachnus eliminated those who still resisted rebelling against the Imperium before moving to purge the Forge World of other dissenting opinions. In what would come to be known as "Trident's Purge," conflict engulfed Arachnus and its two inhabited moons, Iktomia and Nizkara, with later estimates placing the death toll at several million and 37 Titans recorded as having fallen. Following three solar days of extended conflict, the rebellious elements of Arachnus had uncontested control of both the Forge World and Iktomia, though battles still raged upon the surface of Nizkara due to fierce resistance led by a handful of Loyalist Legio Venator Titans. In a message to all within the Belt of Iron, Arachnus pronounced itself as an independent state, declaring punishment for any who defied them. In recognition of this new state of affairs, the traitorous faction of the Legio Venator was renamed the Legio Tritonis in homage to the three celestial bodies, Arachnus and its two moons, from which the Titan Legion hailed. Others knew them by another name, calling them the "Dark Tide" for the widespread destruction they brought down upon any who opposed them.
    • Reckoning (145.013.M31-015.M31) - The loss of Urdesh during the Cataclysm of Iron damaged both the cohesion and morale of the Traitor forces, becoming a symbol of the ascendency of Loyalist forces across the Belt of Iron. While several lesser Forge Worlds such as Tridolii threw themselves on the mercy of the Imperium, others, such as Narunbax, had fallen too far and were in turn crushed by the Legio Venator and the Legio Atarus as the two Titan Legions marched on Arachnus, intent upon recapturing the world in the name of the Emperor. Kalibrax, recognising that the attention of the Loyalists was held elsewhere, retreated inwards, abandoning its allies in an attempt to fortify its holdings. In doing so, the worlds they had conquered were deprived of the presence of the Legio Kulisaetai and with their oppressors removed many of their number rose up once more, casting down those Traitors that remained. Having freed themselves of Traitor rule, many amongst them wished not to stand idle after their long standard years of suffering and gathered in small numbers, seizing control of what ships they could. Together, a vast flotilla of mismatched starships was formed, hundreds in number and eclectic in design. This fleet, lacking a purpose beyond vengeance, fell upon Kalibrax. Millions died against the superior guns of the Forge World yet, as is oft the case in war, numbers proved superior and the fleet seized control of Kalibrax's orbit. Lacking any means of conquering the planet, the Loyalist flotilla vowed to blockade the Forge World until greater forces came to scour the world clean, trapping the Traitors on their planet to do little but await their fate. Arachnus too felt the wrath of the Loyalists. Since announcing their secession, the empire of Arachnus had grown, the name Dark Tide proving apt for their conquests were brutal and swift, and turned upon worlds without a means to defend themselves. These worlds were the first to be reconquered as the Loyalist vanguard carved straight to Arachnus, falling upon its two moons before the wayward elements of the Legio Tritonis could be recalled to defend the planet. On Nizkara, the invading Loyalists found the world heavily contested by those still loyal to the Imperium, the beleaguered defenders having weathered a siege since Arachnus first fell into civil war. The Legio Atarus moved to relieve the moon's defenders, breaking open the Traitor lines and forcing the Legio Tritonis from its surface. On Iktomia, a similar fate befell the Traitors defending it, the full wrath of the Legio Venator brought down upon those who had renounced their oaths and stolen their homeworld. Following the successful conquest of Arachnus' two moons, the Loyalists turned their gaze upon the Forge World proper. With the agreement of those who had been forced into exile from the world, the guns of the two moons were unleashed upon the Forge World, tearing great craters in the planet's surface in order to clear the way for an invading force. Those of the Legio Venator that had defended Nizkara in the Emperor's name were given the honour of being first to stride upon the surface of Arachnus and bring His justice to the Traitors. True conquest was not achieved until after the fall of the Warmaster Horus and the great war that followed, dozens of Titans falling upon Arachnus before the Legio Venator once more reclaimed their home.

Legion Combat Doctrine[]

Iktomia, the first moon of Arachnus, had long ago altered its production capacity in favour of Warlord Titans, which were better suited to fight the mega-arachnids that once plagued Arachnus.

During the Horus Heresy, this era of blood conflict was seen as a way to enact vengeance against the Imperium who had shackled their world to a distant overlord.

In battle, a vanguard of Arachnus tech-cadres would accompany the Legio Tritonis to battle, deploying esoteric devices that could temporarily shroud a portion of the battlefield in impenetrable darkness. Thus, earning their aptly named moniker "Dark Tide" -- both for the use of this mysterious technology and their penchant for massive destruction.

As many of their princeps possessed solar decades or even Terran centuries of service to their former Titan Legion, many princeps within the Legio Tritonis were natural leaders, able to quickly react to their foes and adapt a battleplan to counter any change in fortunes.

Many Dark Tide princeps were highly respected on their homeworld and had an army of retainers, tech-priests and strategists that would gladly follow them into battle.

These princeps viewed damage to their Titans as the greatest insult a foe could give and would strive to ensure the perpetrator was torn apart in return.

Legion Specific Wargear[]

  • Radiative Warheads - Uncaring of the damage done to the planets they conquered, the Legio Tritonis quickly implemented the use of warheads that contained a radiation-heavy payload that placed great strain upon void shields.

Notable Titans[]

  • Bellator Libertas (Warmaster-class Heavy Battle Titan) - The Bellator Libertas. depicted above, was a rare example of a Warmaster Heavy Battle Titan utilised by the Legio Tritonis during the Horus Heresy. The veil of secrecy which surrounded the existence of the Warmaster Titans means it is impossible to verify if Bellator Libertas, which roughly translates to "A Warrior's Freedom," was renamed following the foundation of the Legio Tritonis; the practice of renaming Dark Tide god-engines proved popular following Arachnus' declaration of independence from Imperium and Warmaster alike. Regardless, Bellator Libertas was utilised by Arachnus as a constant deterrent for dissent upon planets the Forge World's armies conquered during the Cataclysm of Iron. Collated testimonies from survivors of numerous invasions by Legio Tritonis forces indicate that the Warmaster Titan would emerge in the final moment of conflict. The Titan Legio would then unleash its might upon a city or military fortification, broadcasting the complete destruction of its target across the planet in question. Few retained the will for rebellion upon watching a single god-engine kill tens of thousands over the course of solar minutes, with surrender to the forces of Arachnus quickly following.
  • Chainbreaker (Warlord-class Titan) - The Warlord Titan Chainbreaker, depicted above in propaganda distributed across the Forge Empire of Arachnus during the Cataclysm of Iron, originally bore the name Sonus est Omnissiah and had served under the banner of the Legio Venator since the 28th Millennium. Like many Legio Tritonis god-engines, Chainbreaker was titled anew following the foundation of the new Titan Legion, shedding its old identity in a public act of renewal.

Notable Personnel[]

None listed in current Imperial records.

Legion Strength[]

Estimates of the strength of the Legio Tritonis following the seccession of Arachnus from the Imperium are based upon comparisons of the surviving strength of the Legio Venator during the Horus Heresy against records collected before the Ullanor Crusade. While exact numbers are impossible to verify, records utilise the predictions of the Legio Venator in their assessment of the Dark Tide, placing the latter's strength between 50-90 god-engines during the Cataclysm of Iron, which would rank it as a Legio of the Secundus or Tertius-prime-grade.

Suspected numbers vary widely thanks to Arachnus' efforts in siphoning resources from the Imperium and the Warmaster prior to its declaration of independence. Having maintained wardenship of Arachnus, the Legio Tritonis also retained control of ancient god-engines previously available to the Legio Venator, allowing it to field rarer patterns such as several Nemesis Titans and two known Imperator Titans.

Legion Appearance[]

Dark Tide Icon Fancy

Legio Tritonis variant Legio iconography

Legion Colours[]

This rebellious Titan Legion's colours are primarily grey with dark green painted on their god-engines' massive shoulder plates and portions of the Titan's head.

Dark green and grey iconography was often used, as well as green chevrons painted upon Titans' lower legs.

Legion Badge[]

This Titan Legion's badge is a black trident crowned by an Iron Halo and centred upon a red circlet surrounded by a field of black.