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Warhammer 40K: Heavy Metal – the Leviathan Siege Dreadnought

4 Minute Read
Jun 22 2022

Today we look at the rarely seen unstoppable mountain of metal that is the Leviathan Dreadnought. The strongest are strongest alone!

The Leviathan pattern Siege Dreadnought was a large type of Space Marine Dreadnought used during the Great Crusade and Horus Heresy by the Legiones Astartes.

Dreadnought Basics

A Space Marine Dreadnought is a large, walking tank which carries both powerful guns and lethal close combat weaponry, armoured to withstand all but the most powerful of enemy firepower and often relied on by Space Marine forces to tear an opening in enemy defenses. Each Dreadnought contains a living being, permanently interfaced with the machine through a form of Mind Impulse Unit. Dreadnoughts are surprisingly agile, able to walk and balance with the ease of a living creature.

It is said that old proto-Dreadnoughts of the Unification wars could be piloted by non-Adeptus Astartes warriors, but later only Space Marines could be interred in them.

Great Crusade era Dreadnought Cutaway Illlustration

The pilots within Dreadnoughts are Marines who have suffered mortal wounds in battle, maimed and crippled beyond recovery – instead of being mercifully killed, the greatest heroes are instead given what is considered the honour of continuing to serve the Emperor past their normal life. Once interred within the Dreadnought, the Marine cannot leave the metal womb and is destined for a life of endless battle until destroyed. Some are so ancient their memories may extend back to the founding of their chapter and its earliest history. For this reason they are revered not just as powerful warriors but also as ageless forebears and living embodiments of battles fought long ago. If a dreadnought is destroyed, the Space Marines will fight to retrieve the armoured shell so that the occupant can be returned to the chapter’s mausoleum for his long-deserved final rest.

Dreadnought machines themselves are ancient, the oldest dating back tens of thousands of years to the Age of Strife. Because the art of constructing them has been almost lost, Dreadnoughts are revered as rare machines, though the most revered specialists still dare to construct ‘new’ Dreadnoughts.

Imperial Fists Leviathan Dreadnought

Leviathan Dreadnought Overview

Built in limited numbers during the latter days of the Crusade, the Leviathan was developed in secret on Terra without the knowledge of the Mechanicum. Its massive frame incorporates hybridised technologies, some dating back into the Dark Age of Technology. The resources to build these machines were nearly equal to that of a Knight Towering over later Imperial walker patterns, this heavily armoured dreadnought is savagely powerful.


Those few Leviathan Dreadnoughts which survive into the 41st Millennium are ancient and terrible relics, rarely spoken of and rarely deployed, dreaded as much as they are revered by those Chapters that possess them. The tormented and ravaged minds of those interred within are driven to the edge of madness by the little-understood mechanisms unique to the Leviathan, trapped in dreams of the 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 Chapter Master 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.

Death Guard Leviathan Dreadnought Talon


The Leviathan Siege Dreadnought bristled with weaponry, including two arm mounts that could be equipped with a combination of a Leviathan Storm Cannon, Grav Flux Bombard, Cyclonic Melta Lance, Leviathan Siege Claw, and Leviathan Siege Drill, the latter two of which would incorporate a meltagun. Its torso was equipped with a pair of Heavy Flamers or twin-linked Volkite Calivers. Additional weaponry could include up to three Hunter-Killer Missiles and/or a Phosphex Bomb discharger. Finally, it would typically be armed with frag and smoke grenades, as well as a spotlight.

White Scars Leviathan Dreadnought

41th Millenium Legacy

While the Leviathan is extremely rare today, some machines still remain in service. Most notable is Carab Culln, Chapter Master of the Red Scorpions. Chaos Space Marines still use ancient Leviathan Dreadnoughts, which have since become Daemonically corrupted.

~The flesh is weak

Learn More of Space Marine Dreadnoughts



Blood Angels Leviathan Dreadnought

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