27 Oct 16

Power Armour Through the Ages


Space Marines are the most instantly recognisable of all Citadel miniatures, not least because of the distinctive power armour they wear, in all its many marks. Here we take a look at the design and evolution of this iconic armour, in more detail than ever before…

In Ceramite Clad
Ceramite is a form of bonded ceramic armour, incredibly tough, but light. Unlike metal, it doesn’t dent or rupture on impact and it takes a projectile of significant power and calibre to punch through it. Repairs are made by bonding new layers of ceramite over existing ones. Ceramite also conducts relatively little heat, making it ideal against heat-based and high-energy weaponry.

Over the last 30 years, Space Marine power armour has gone through many stages of development, both in the background of Warhammer 40,000 and in the real world of miniatures design. The result is eight distinct iterations, or marks, of power armour, each with its own history and unique design elements. Here we present the story of Space Marine power armour, from its inception during the conquest of Terra and its rapid evolution during the dark days of the Horus Heresy, right up to the present day in the war-torn galaxy of the 41st Millennium.

Not only that, but we also look at how the design of power armour has evolved over the last 30 years, with some insights into the development of each design. In the universe of Warhammer 40,000, these marks of armour represent a series of linear developments but, interestingly, these eight marks were not designed in order, the designers often going back to create older marks to fill in the gaps in its evolution, each new design reflective of a different period in the history of the Imperium. Read on, then, for the history of power armour…


Mk. I ‘Thunder’ Armour

mkithunderThunder armour was first worn by the Emperor’s proto-Space Marines during the reunification wars on Terra. Neither fully enclosed nor airtight, it cannot be considered true power armour, but paved the way for future designs. It featured a powered and heavily armoured torso that gave the wearer immense upper-body strength for grappling and subduing their foes. The power required to keep the suit working came from a backpack, a technological innovation that has been incorporated into every mark of power armour since. Its name was derived from the thunder and lightning symbol on the armour’s plastron.


  • Thunder Warriors are rarely mentioned in the background, yet one called Babu Dhakal (originally known as Arik Taranis) appears in the Horus Heresy novel The Outcast Dead.
  • Thunder armour was one of the last marks of power armour to be sculpted, the model intended as a collector’s model to complete the set rather than as a gaming piece.

Mk. II ‘Crusade’ Armour


Following the conquest of the Sol System, the Emperor re-equipped his Space Marine Legions with Crusade armour, the first iteration of true power armour. Environmentally-sealed, it could protect the wearer from the very worst battlefield conditions, even in the depths of space. It featured articulated sections of hoop-shaped armour, both on the torso and legs, giving the Space Marine unparalleled mobility, and a more efficient power system to prevent overheating. Regarded by many as the most effective suit of power armour, it was notoriously difficult to maintain and dropped out of common use by the 41st Millennium.


  • The Mk. II’s helmet was originally fixed to the gorget, meaning it would not turn with the wearer’s head. When Forge World released sets of Mk. II armour, they redesigned the helmets to enable more modelling options.
  • The helmet was also the first part of the armour to be designed, drawn first in early concept sketches, with the armour then designed to match.

Mk. III ‘Iron’ Armour

mkiiiironIron armour was developed during the Great Crusade, not to replace Crusade armour, but to be used alongside it in close-quarters boarding actions and tunnel fighting. Ostensibly a suit of modified Crusade armour, it featured additional armour panels on the greaves, forearms, thighs, chest and groin, plus larger shoulder pads and a more angular helm to deflect bullets away from the face. To compensate for the heavy front plates, Iron armour was not reinforced at the back, making it ideal for frontal assaults and battles in claustrophobic environments, but unsuitable for regular combat duties. It is now mainly worn as ceremonial armour.


  • The Ultramarines tank commander Sergeant Chronus wears a suit of Mk. III Iron armour.
  • The MK. III helmet was loosely based on a medieval frog-mouthed helm, but with a more industrial feel to it. The helmet design was used as the starting point for the helmets worn by the power-armoured Grey Knights models that came out 20 years later.

MK. IV ‘Maximus’ Armour

mkivmaximusAs the Great Crusade spread throughout the galaxy, the Emperor’s Legions required a constant supply of power armour to replace those suits damaged in battle. Mk. II and III armour proved notoriously difficult to maintain, so the Mk. IV suit was created to replace it. Lighter, more efficient and with a higher power output than previous suits, Maximus armour used new technology gleaned from worlds reconquered during the Great Crusade. The armour was the first to feature armoured power cables on the outside of the breastplate and the first to have a helmet that moved with the wearer’s head, thanks to innovations in neural technology.


  • The backpacks worn by Space Marines were originally meant to be jet packs – there’s even a piece of artwork in the 1988 Warhammer 40,000 supplement Chapter Approved that showed them using them. The round nozzles on either side of the backpack are now categorised as stabiliser jets for use in zero gravity.

Mk. V ‘Heresy’ Armour

mkvheresyAs brother turned on brother during the Horus Heresy, suits of power armour became increasingly battle-damaged and unusable. With the Mk. IV not yet in full production, many Legions had to cobble together suits from whatever they had available. The Mk. V was the result. The suit featured older, bulkier cabling than the Mk. IV, which had to be housed outside the armour – a major but unavoidable design flaw. It also featured additional armour panels on the shoulder pads and greaves, which were held on by molecular bonding studs. The additional weight was considerable, making the suit cumbersome and prone to overheating.


  • Designing older suits of power armour proved quite tricky at times. They had to look older and less developed than Mk. VI and VII power armour, but in the background they were described as more technologically advanced. Heresy armour proved one of the hardest designs to work on, an amalgamation of old and new designs on one suit.
  • The bulldog-like Mk. V helmet is based on the Terminator helmet.

Mk. VI ‘Corvus’ Armour

mkvicorvusWith production of Mk. IV power armour severely limited by the Horus Heresy, a new mark of armour was required as a permanent replacement: the Mk. VI ‘Corvus’ armour. The suit, which takes its name from the Raven Guard Primarch, was the first to feature dual technology circuits, the external power cables on the torso backed up by failsafe circuits built into the armour. All other cabling was hidden beneath ceramite armour plates, including newer and much heavier leg greaves. Primarily distributed to loyalist Legions during the Horus Heresy, suits of Mk. VI power armour are still used by many Chapters almost 10,000 years later.


  • The Space Marines in the first Warhammer 40,000 plastic kit (the now famous RTB01 box) wore Mk. VI power armour.
  • The RTB01 models were meant to have boots like the first Imperial Space Marine, but the injection moulding technology of the late 1980s made it impossible. Instead, they were redesigned with flared greaves, a design that’s been synonymous with Space Marine power armour ever since.

Mk. VII ‘Imperator’ Armour

mkviiimperatorMark VII armour, also known as Imperator, Eagle or Aquila armour, is the most common armour worn by Space Marines in the 41st Millennium. The armour features a heavy plastron, built to accommodate the chest cabling (the only real weakness on the Mk. VI), which is emblazoned with an aquila to show allegiance to the Emperor. The snub-nosed helmet was, once again, a derivation of the Mk. IV helmet design, but made more compact so it was easier to wear in combat. One of the defining features of the Mk. VII is that its parts are compatible with many older marks of armour, particularly the Mk. VI, making essential repairs far easier.


  • The face grille on the Mk. VII armour came about because the designers wanted to make the Space Marine helmet look more aggressive. The brow was made more pronounced to emphasise the effect. The Rogue Trader rulebook even features a conversion of a Space Marine in Mk. VI power armour with his nose cut off! He’s regarded as the first step on the Mk. VII design path.

Mk. VIII ‘Errant’ Armour

mkviiierrantErrant Armour was conceived in the wake of the Horus Heresy. Despite being the latest design of power armour, it is rarely seen in the 41st Millennium. On the surface, Errant armour looks much like a suit of Mk. VII power armour, but with all the torso cabling hidden behind articulated armour panels. Additional armour to protect the ribbed joints can be seen at the hips, and the ankles of the greaves have been adapted to provide better range of movement. The biggest change is the raised gorget, developed to protect the neck seal on the helmet where bullets were sometimes deflected by the armour’s sloped breastplate.


  • Mk. VIII armour was an adaptation of Mk. VII armour, both in the background and in real life. It was actually the third suit of armour to be designed, though among the last to appear as a miniature.
  • Errant armour has been around for thousands of years, but rarely seen in the 41st Millennium. Why might that be, we wonder…?

And what of the traitors?

traitorsThe first designs for Mk. II, III, IV and V power armour were, in fact, produced for Chaos Space Marines, way back in 1990. It was thought that while loyalists in the 41st Millennium would wear newer marks of power armour, the traitors of the Horus Heresy would be confined to maintaining and wearing older suits. The first concept drawing for the low-tech Mk. V suit was a Khorne Berzerker, while the Thousand Sons wore the more advanced Mk. IV armour. The Plague Marine to the left was made wearing a heavily armoured Mk. III suit to reflect the Legion’s propensity for gruelling frontal assaults.


  • When Mk. VII became the predominant power armour design in the 1990s, the miniatures rarely had an aquila on the chest. Indeed, most Space Marine models of the time featured a winged skull or gem. The aquila only came into regular use in 1997 when the all-plastic Tactical Squad boxed set was released. The winged skulls stayed around, but, according to design legend, all the gemstones were stolen by the Eldar.