A Leviathan Pattern Siege Dreadnought of the Death Guard Legion during the Horus Heresy

Created in limited numbers in the latter days of the Great Crusade of the late 30th Millennium, the Leviathan Pattern Siege Dreadnought or more simply, the Leviathan Dreadnought, was developed in secret on Terra, away from the pervasive oculars of the Mechanicum. Its massive frame incorporates hybridised technologies, some dating back into the dim past of humanity. Towering over later Imperial combat walker patterns, this heavily armoured Dreadnought is savagely powerful.

It was designed for siege warfare and primarily armed with close combat and support weaponry that can rend buildings, vehicles and flesh alike; though it is no less effective when armed with the powerful and esoteric short-ranged weaponry uniquely developed for it. The Leviathan's oversized Atomantic Reactor allows it to bear weapons more powerful than other classes of Dreadnought, and also powers reinforced energy fields that surpass those developed for the Contemptor Pattern Dreadnought. Power has its cost though, and the systems of the Leviathan place a lethal level of strain on the minds of its occupants. Space Marines who find themselves interred within a Leviathan will pay a heavy toll; either with their life, or their reason.

Those few examples of Relic Leviathan Dreadnoughts which survive into the late 41st Millennium are ancient and terrible relics, rarely spoken of and rarely deployed, dreaded as much as they are revered by those Chapters in whose armoury vaults they reside and stand empty until direst need. The tormented and ravaged minds of those Astartes interred within are driven to the edge of madness by the little-understood mechanisms unique to the Leviathan, trapped in gore-soaked dreams of the lost Age of Darkness during the Horus Heresy which haunt the machines themselves, and soon suffer a final dissolution owing to the terrible strain the Leviathan inflicts on those who would dare to master it. Only the full authority of a Master of the Chapter is sufficient to unleash these terrifying machines in war, as where they strike and what they kill is as often determined by their dark dreaming as it is the will of their commanders.


Developed in the highest secrecy not on Mars, but on Terra, the Leviathan was an alternative development of the highly successful Contemptor Dreadnought. It represents hybrid technologies, some of which it is believed date back to the Age of Strife, which rumours had it were created by the hand of the Emperor directly. The resources required to produce one were immense, equal perhaps even to an Imperial Knight. Made available to the Legiones Astartes only in limited quantities before the outbreak of the Horus Heresy, they were highly valued and recognised as savagely powerful siege and hunter-killer units. They placed an onerous and ultimately lethal strain upon their occupants, the Leviathan's incumbent burning brightly but briefly in their second life. Many in the Mechanicum were deeply uneasy over the design, seeing it as purpose-designed to match and indeed destroy the Mechanicum's own Battle-Automata in some future, unforeseen crisis or dispute between them and the wider Imperium.

During the Horus Heresy, Loyalists with access to Terra were able to obtain new Leviathan Dreadnoughts, although never many, while Traitors and isolated forces were reduced to marshalling their few Leviathans carefully or hunting down the relics of the dead from the battlefields to be re-commissioned.

Unit CompositionEdit

  • Leviathan Pattern Siege Dreadnought Talon - Wherever possible, Leviathan Dreadnoughts would be fielded in a so-called "Talon" of three Dreadnoughts, making the most of their versatility with multiple, independent weapon load-outs.

Notable Leviathan Pattern Siege DreadnoughtsEdit

The following are notable Leviathan Pattern Siege Dreadnoughts:


Ancient-Reductus Vakuran, a Leviathan Dreadnought of the Night Lords Legion

  • Ancient-Reductus Vakuran - Vakuran was a Leviathan Dreadnought of the Night Lords Legion. Before being interred within a Dreadnought, Ancient-Reductus Vakuran had fought during the later stages of the Unification Wars on Terra and eventually fell in combat against a mighty Over-wyrd of the Hambro-Cuth. Later, sometime after the outbrak of the Horus Heresy, he would be sealed within his Leviathan Pattern Dreadnought after it was captured from the Ultramarines Legion at Xorthorn VII, the Night Lords ripping the still-living body of its previous owner out and casting him upon the bloody ground. While interred within his Leviathan Dreadnought, Vakuran is known to have participated is dozens of campaigns across the Ultima and Tempestus Segmentums. In each case he led the forces of the Night Lords in direct assaults against heavily-defended Loyalist positions. In each assault his attacks were described as direct, brutal and crude, leading observers to suspect that he had been driven to the edges of sanity by the strain of operating the highly-demanding systems of the Leviathan Dreadnought.
Ancient-Claviger Khalon

Iron Hands Leviathan Siege Dreadnought, Ancient-Claviger Khalon, Heavy Assault Echelon, Order Novii, Morragul Clan-Company during the Horus Heresy

  • Ancient-Claviger Khalon - Khalon was a Leviathan Pattern Siege Dreadnought of the Iron Hands Legion's Morragul Clan-Company. Once a Legion Consul of the Ungavarr Clan-Company, Ancient-Clavigar Khalon was a Terran-born siege-breaker of great renown, having won countless honours during the early days of the Great Crusade. Khalon fell in combat during the apocalyptic Battle of Rust, and was barely saved by Legion Apothecaries. His body was placed in stasis so that he could later be interred within a mighty Dreadnought. When at last a Dreadnought shell was available, it was to be a prototype class intended for heavy assaults and siege warfare, a perfect fit for the renowned siege-breaker. Upon being placed within his new Dreadnougth form, Khalon was found to be mentally ill-suited to his new existence and was prone to bouts of extreme instability. At the order of Ferrus Manus himself he was transferred form Clan Ungavarr to Clan Morragul, where his demeanour was considered to be more suited to the orphans and outcasts that had gathered under the stewardship of Iron Father Autek Mor.

Carab Culln of the Red Scorpions Chapter after his transformation into a Relic Leviathan Dreadnought known as "Carab Culln the Risen"

  • Carab Culln the Risen - Carab Culln is the former Lord High Commander (Chapter Master) of the Red Scorpions Space Marine Chapter and a current Relic Leviathan Dreadnought. Known throughout the Imperium, he is a warrior of great courage and battle experience who has fought the enemies of Mankind across the breadth of the galaxy. Renowned as an inspirational leader of unimpeachable bravery, Carab Culln had the honour of being selected as Magister Militum (supreme commander) of the Loyalist Space Marine forces during the internecine conflict known as the Badab War from 904.M41 until 912.M41. During his baptism of fire as a Chapter Master during this conflict, he preferred to lead the major actions of the war from the front, earning the respect and admiration of his peers. Carab Culln was believed lost to the Imperium in the campaigns that followed the Indomitus Crusade. Grievously wounded in the slaying of the Great Beast of Sarum, Culln's remains were returned to the Chapter, bearing only the faintest whisperings of life. Thus in honour he was interred within the armoured shell of a Relic Leviathan Dreadnought, blessed with the technology to allow Culln to serve his brethren in battle once again as Carab Culln the Risen.


Optional WargearEdit

  • Twin-Linked Volkite Caliver  - A Volkite Caliver is one of an ancient class of weapons whose arcane name is used by the Adeptus Mechanicus to refer to an entire class of powerful thermal ray weapons whose technology is pre-Imperial in origin and dates back to the Age of Strife. These weapons possessed considerable killing power, surpassing most other armaments of their size. Blasts from Volkite Weapons were even known to be able to penetrate the thick ceramite plates of Space Marine Power Armour with one concentrated shot. Volkite Weapons produced a deflagrating attack, in which subsonic combustion caused by a beam of thermal energy propagated through a material by thermodynamic heat transfer so that hot burning material heated the next layer of cold material and ignited it. A Volkite Weapon's heat ray had a devastating effect on organic matter, explosively burning flesh into ash and jetting fire.
  • Leviathan Siege Drill with built-in Meltaguns - The close-combat weapons of the Leviathan Pattern Siege Dreadnought were developed to be even more destructive than those of other Dreadnoughts. The Leviathan Siege Drill was designed to bore straight through the heavy armour of armoured vehicles. It also incorporates a Meltagun and, as with all of the Leviathan’s close-combat weapons, excels at tearing through the walls of enemy fortifications.
  • Armoured Ceramite Plating
  • Three Hunter-Killer Missiles
  • Phosphex Bomb Discharger - This dispenser unleashes Phosphex Bombs upon the target. A Phosphex Bomb and its artillery counterpart, the Medusa Shell, are arcane incendiary weapons utilised by the military forces of the burgeoning Imperium of Man during the Great Crusade and Horus Heresy eras. Phosphex was a rare corrosive toxic and incendiary compound utterly inimical to life, deployed both in the form of large canister bombs (called Phosphex Bombs) and heavy artillery shells (the horrific Medusa Shell). It expands on contact with air into a seething, liquid mist which burns with an eerie white-green flame which is attracted to movement. This gelid flame ignites metal and eats relentlessly into living tissue, and cannot be extinguished short of exposure to vacuum. Though highly effective, this horrific weapon was only primarily used as a weapon of last resort.
  • Leviathan Storm Cannon - The ranged weapons of the Leviathan pattern Siege Dreadnought were designed to be used at closer range than those carried by most classes of dreadnought. The Leviathan Storm Cannon is a rapid firing multi-barrelled weapon, purpose built to scythe down infantry and clear out the defenders of tactical objectives.
  • Cyclonic Melta Lance - This rapid cycling melta beam weapon is utilised for fortress breaching, enabling a Leviathan Siege Pattern Dreadnought to cut through the thickest plated armour with ease.
  • Grav Flux Bombard - The ranged weapons of the Leviathan pattern Siege Dreadnought were designed to be used at closer range than those carried by most classes of dreadnought. The Leviathan Grav-flux Bombard creates a spiralling vortex of gravitation-torsion force. It is a fortress-breaching weapon which can reduce the toughest armour to twisted scrap and crush anything living beyond recognition.



Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.