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Deimos, known also as the "Steel Forge", was once one of the two moons of Mars which now serves as a major Forge World for the Daemon-hunting Grey Knights Space Marines, the Chamber Militant of the Inquisition's Ordo Malleus.

This Adeptus Mechanicus realm, now located in orbit of their Chapter homeworld of Titan, itself a moon of Saturn, is devoted exclusively to providing the Chapter with arms, munitions and war machines.

In theory, the Grey Knights have access to any pattern of war machine ever wrought by the hands of the servants of the Machine God, but in practise they limit the use of armoured transports to the mighty Land Raider and a few other key armoured fighting vehicles and aircraft.


The war needs of the Grey Knights call for a constant supply of ammunition and ordnance. Long ago, upon the inception of this secret Chapter, the Grey Knights made an alliance with the Adeptus Mechanicus and as part of their bargain were gifted with the Forge World of Deimos.

Tasked with directly combating the daemonic threat, it was recognised that they would need their own Forge World. Using arcane technologies, Deimos, one of the heavily industrialised moons of Mars, was stolen out of its orbit, dragged across the Sol System and secretly relocated above Titan, the shrouded homeworld of the Grey Knights, its mass mined and converted until it was more star fort than celestial body.

Deimos is blessed with a great many macroclades, all bearing the triple blessing of the Omnissiah. Additionally, no fewer than three Knight houses are permanently stationed upon Deimos, including House Steel, whose vows of silence in service to the Adeptus Mechanicus have lasted since the Great Crusade.

Deimos' armies are used as guardians, as procurement forces, and upon request, are sent to march forth in battle alongside the Grey Knights.

Notable Campaigns

Deimos Forces Appearance

The official Imperial stamp of the Forge World of Deimos

Deimos Iconography

The strange esoteric tech-glyph of Deimos, whose exact meaning is unknown to outsiders, is borne proudly by the nuermous macroclades of this Forge World.

Deimos Forge World Colours

Deimos' Skitarii bear sinopia coloured armour plates and sky blue robes, whose interior is white.

The white toothed iconography which rings the hoods, sleeves and hems of their robes is reminiscent of the teeth of a cog, a sacred symbol of great significance to all the Tech-priests of the Cult Mechanicus.

The armour and weapons of the warriors and Tech-priests of Deimos is always adorned with brass trim.

Manufactoria Capabilities

A Deimos Skitarii

Since the relocation of this Forge World from its position as a moon of Mars to the orbit above Titan, the weapons required by the Emperor's Daemonhunters have been produced by the manufactoria of Deimos.

This includes standard Adeptus Astartes armaments as well as all the specialist gear required to combat Warp-based foes, from Psycannon ammunition to deadly Psyk-Out Grenades. Each item receives psychic wards atop the blessings of the Omnissiah to ensure protection against daemonic taint.

Only the Nemesis force weaponry is created in the citadel by the Grey Knights Techmarines themselves; all other materiel is ferried down from Deimos in an endless stream of heavily-guarded transports.

Especially debilitated servitors oversee the packing and transportation of everything destined for Titan, loading consignments in utmost secrecy to ensure that no one, not even the Tech-magi of Deimos, know the extent of the Grey Knights' arsenal.

The same servitors are then mind-wiped and their circuits scrubbed clear before their return to Deimos, lest the enemies of the Imperium were ever to dissect their shrivelled brains.

Such extreme measures ensure that the secrets of the Grey Knights can never be learned by the Tech-priests -- and, conversely, that the psychic Grey Knights cannot themselves glean any of the clandestine mysteries of the Adeptus Mechanicus.


  • Fury of Deimos - When the Martian moon of Deimos was gifted to Titan by the Adeptus Mechanicus, it carried with it a voidship loaded with some of the finest weapons the Imperium has ever created. Among them was the Storm Bolter Fury of Deimos, a weapon crafted by the first Fabricator-General of the Mechanicum. Superior in range, accuracy, rate of fire and reliability to a normal Storm Bolter, it is a relic whose secrets have long been forgotten.


  • Codex: Adeptus Mechanicus (8th Edition), pp. 15, 22, 35
  • Codex: Grey Knights (7th Edition), pp. 25, 182, 208
  • Codex: Grey Knights (5th Edition), pg. 11
  • Imperial Armour Volume Two: Second Edition - War Machines of the Adeptus Astartes, pp. 204-205