Accatran is a major Imperial Forge World of the Adeptus Mechanicus located in the Ultima Segmentum known to have achieved a production grade of IV-Secundi. Situated on the edge of the Ork Empire of Charadon, Accatran is the homeworld of the Adeptus Titanicus' Legio Destructor ("Beasts of Steel").


Much of the early history of this notable Forge World has been lost down the long millennia. It was settled sometime during the Dark Age of Technology by early Mechanicum Explorators. When the realms of Mankind were cut off by raging Warp Storms created by the birth pangs of the Chaos God Slaanesh that heralded the dire era known as the Age of Strife, it was the legendary warrior-magos Xerxes Importalus who preserved Accatran through the terrors of that era during his thousand-year reign.

In honour of this revered Magos, the combined armed forces of Accatran, the Taghmata Xerxes, took its name from Xerxes Importalus.

The Great Crusade

During the Great Crusade era, within the fledgling Realm of Ultramar, there were as yet no Forge Worlds of the magnitude of ancient Accatran, with only the newly established Forges of Anuaris, still tied both in tribute and loyalty to distant Accatran as much as Macragge, and the reclusive Magi of the iron-bound moon of Gantz ranked as true Forge Worlds within the boundaries of Primarch Roboute Guilliman's fiefdom. However, there did exist a large number of Mechanicum enclaves scattered throughout the Five Hundred Worlds of Ultramar.

The Horus Heresy

Adeptus Mechanicus stellar cartographic map of the Forge Worlds of the Segmentum Ultima, including the Forge World of Accatran.

The Calth Conjunction

After having received the order from Warmaster Horus (who had already been corrupted secretly by the Ruinous Powers) to muster the XIII Legion for war upon Calth, Guilliman called on not only the many contingents of the Ultramarines scattered across the galaxy, but also those fiefdoms of the enigmatic Martian priesthood that dwelt within the expanding borders of his own domain, the Five Hundred Worlds of Ultramar. Such a realm, as dependent as it was on the technological gifts of the Mechanicum to both provide for its people and to protect its borders, was home to a number of significant Machine Cult enclaves as well as several fully-fledged Forge Worlds, such as Accatran.

When the Lord of Ultramar called, they were bound to supply warriors for his cause. On the larger Forge Worlds of the Imperium in this era, these forces, the Taghmata Omnissiah, could rival even the Legiones Astartes ' Chapters in size. One such force was the Taghmata Xerxes, the battlegroup despatched from the Forge World of Accatran to join the gathering force at Calth whose Third Quinternary Division comprised nearly 15,000 combatants alone, being an approximate one fourth of Taghmata Xerxes' full strength.

Battle of Calth

The Third Quinternary Division was a long-standing veteran formation which had over the years served many masters during the Great Crusade on a score of battlefields, and thus warranted a specific assignment within the Traitors' ranks as their nemesis when battle was joined.

This nemesis was to be the Ordo Reductor Covenant of Mormoth-Null, who remained in orbit before the attack and was also given the task of destroying a number of strategic targets in the void-dock city of Ithraca where the bulk of the Taghmata Xerxes were based. When the Word Bearers and their Chaos-aligned Traitor allies revealed their perfidy and turned their guns upon their erstwhile brethren, those Loyalist forces still loyal to the Throne of Terra were caught completely by surprise.

While the internecine slaughter was at first largely confined to the forces of the Imperial Army stationed around Ithraca and in the mustering camps beyond, other off-world forces from the Taghmata Xerxes to the Titans of Legio Praesagius were at a loss as to how to react, unsure of just who the enemy was or whether some vast accidental calamity was unfolding around them, the true danger not apparent until it was far too late.

The Battle-Automata cohorts and armoured squadrons of the Taghmata Xerxes miraculously weathered the storm. After suffering initial losses from the orbital attack, they also fell back towards the city, selecting a heavy industrial zone in its southern quarter as affording the greatest cover.

Traitor Imperial Army auxiliaries in the form of the Mordechai Occlusion regiments had thought to bar their way, but the Feudal World-raised troops possessed only relatively light armaments and proved no match for the Taghmata, which pitilessly eradicated the chanting assault waves, killing thousands, while Mechanicum-affiliated Knights secured the Taghmata's flanks as it advanced en masse into the industrial zone. The initial wave of slaughter and destruction was over. Now the stage was set for the Battle of Ithraca's second bloody phase.

By the end of the first solar hour of the Battle of Ithraca, the western sectors of the city had become the scene of a deadly conflict between Titans, the most powerful of all the Imperium's war machines, in a clash of unprecedented scale and ferocity.

Meanwhile, wave upon wave of other Traitor Auxilia and Chaos Cult forces began to hurl themselves against the improvised defences and barricades the Taghmata Xerxes had quickly set up in the southern industrial zone they had marked for their stand against their foes. These waves came so thick and so fast that the carefully calculated kill zones became swamped with bodies, and the weapons of the defenders began to overheat and magazines ran dry, such was the relentless, suicidal fury of the enemy.

Spurred on by Heretic Astartes of the Word Bearers Legion's Chapter of the Unspeaking, who brought with them recognisable Legiones Astartes heavy armour and weapons, as well as devices of unrecognised pattern and murderous power which, in conjunction with the relentless human and Abhuman attack waves, started to cause significant damage to the hard-pressed Battle-Automata and Adsecularis cohorts of the Taghmata Xerxes.

Vastly outnumbered and now seriously threatened, the Taghmata were forced to slowly begin giving ground so that they could fall back in an ever-shrinking series of redoubts and hastily, though efficiently organised, defensive perimeters. After several solar hours of intense fighting, matters for the Taghmata Xerxes were becoming increasingly desperate.

The arrival of a house of Loyalist Knights from the stranded House Vornherr detachment at Ithraca had bought a temporary respite, but the Xerxes had shortly afterwards found themselves pinioned between the living waves of Word Bearers-driven cult troops and the crimson and black liveried Siege-Automata of the Ordo Reductor of the Traitor cohort of Covenant Mormoth-Null, which had sought them out for destruction.

While the scions of House Vornherr bought time with their steel and their blood, the Magi of the Taghmata Xerxes, cut off from outside contact and aid, enacted a desperate plan, working feverishly to dismantle and reconfigure a large Plasma Reactor unit which had been until then the beating heart of one of the great manufactoria of the city, the plasteel-clad ruins of which now constituted the Taghmata's final redoubt.

Seven point six solar hours after the battle had commenced, the Taghmata Xerxes launched its counterattack. Utilising its last reserves of Castellax-class Battle-Automata as a fighting wedge, relying on their servo claws and power blades to cut their way through the enemy, the charge of the Battle-Automata cleared a path to the heart of the Word Beaers-driven horde.

Into this breach, three damaged but still-functional Thanatar-class Siege Automata dragged the modified reactor, now rebuilt into a highly unstable plasma bomb of prodigious explosive power. Oblivious to their fate, the cultic horde drove on afresh to the attack, while high above aboard the Dirac's Lament, the master of Covenant Mormoth-Null, the Archmagos Barbatos Hexad, known as "the World" to the commanders of the Great Crusade, perceived the danger and ordered an immediate withdrawal, but it was too late.

Having determined that victory was logically impossible, the Magi of the Taghmata Xerxes activated a program of mutual destruction, detonating the bomb. An area of roughly a half kilometre in diameter was immediately burned to vapour, while beyond that, the blast wave reached out to ravage an area equivalent to twenty-three city blocks, charring flesh to cinder and twisting metal into smouldering wreckage.

The sacrifice and determination of the Taghmata Xerxes would not be in vain, as the Loyalist forces would ultimately turn the tide against the hated Traitor forces.

Notable Campaigns

  • Battle of Calth (007.M31) - Mustering at Calth on orders issued by the Warmaster Horus before Istvaan, the Ultramarines and Word Bearers Space Marine Legions, along with the forces of several Forge Worlds, including Accatran, prepare for a campaign against the Orks of the Ghaslakh xeno-hold. The Ultramarines are unaware of the Word Bearers' true allegiance and utterly unprepared for betrayal, and suffer horrific losses. The Traitors' real objective is the murder of the Veridia star of the Calth System as an offering to the Ruinous Powers that would bring about the Ruinstorm, a Warp tempest so large, it would sever the galaxy in half and render all long-range Warp travel unpredictably dangerous, and trans-luminal communication all but impossible. The Age of Darkness of the Horus Heresy begins.
  • Rain of Fire (ca. 745.M41) - After the Battle of Macragge, a splinter fleet of Hive Fleet Behemoth winds its way into the Skitarii-held Daugel Helix. Using the knowledge recovered from the Tyran data-codex, the Skitarii fight back. The cohort commander Alpha 9-Thyrrc turns the tide by saturating a stratum of the atmosphere with gas from the planet's Promethium refineries. After his Onagers' neutron lasers set the skies aflame, each new rain of Tyranid spores incinerates those xenos planetside instead of reinforcing them. A triumphalist data-codex is compiled and sent to the nearby Forge World of Accatran, where it is swiftly filed away in the Archive Anomalis and forgotten.

Notable Accatran Personnel

  • Xerxes Importalus - A legendary warrior-magos whose thousand-year reign helped to preserve Accatran through the horrors of Old Night.

Manufactoria Capabilities

Accatran is known to produce its own patterns of weapons utilised by the forces of the Astra Militarum, especially the regiments of the Elysian Drop Troops and other drop troops because of the weapons' light weight, which includes: Laspistols, Lasguns, Shotguns, Grenade Launchers, Plasma Weapons and Meltaguns.

With its natural resources and atmosphere all but gone, the planet has been rendered inhospitable to all except Space Marines and the Mechanicus locals, who use cybernetic enhancements to survive the deadly environment. Little else is known of this Mechanicus Forge World in official Imperial records.


  • Codex: Adeptus Mechanicus (8th Edition), pp. 13, 34
  • Imperial Armour Volume One - Imperial Guard and Imperial Navy, pg. 8
  • Imperial Armour Volume Four - The Anphelion Project, pg. 136
  • Imperial Armour Volume Six - The Siege of Vraks - Part Two, pg. 149
  • Imperial Armour Volume Eight - Raid on Kastorel-Novem, pg. 92
  • Imperial Armour Volume Eleven - The Doom of Mymeara, pg. 101
  • The Horus Heresy - Book Five: Tempest (Forge World Series) by Alan Bligh, pp. 33, 52, 54-55, 57-59, 60, 62, 64, 133-134, 137


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