Power Armour

Power Armour is an advanced form of combat armour, worn primarily by the Space Marines and the Chaos Space Marines. It is a completely enclosed suit of combat armour composed of thick ceramite plates that possesses a full suite of life-support functions for operation in hostile environments, an automated medicae system to provide some level of first aid to a wounded wearer and a highly advanced and fully integrated tactical targeting and threat analysis system. The armour would be heavy and cumbersome to wear but for the electrically motivated fibre bundles within the armour that replicates the wearer's movement and enhances his strength beyond its already considerable superhuman baseline (for Space Marines). Whilst Power Armour is most commonly associated with the Space Marines of the Adeptus Astartes, the Sisters of Battle and many Inquisitors also use powered armour of one sort or another. Typically, however, these armours may not contain the same strength-enhancing properties or life-support functions of Space Marine Power Armour, nor do they always provide the same level of protection.

Design
Power Armour is fully sealed, isolating the wearer from the outside environment and protecting him from chemical and/or biological weapons and toxic atmospheres. It also commonly includes numerous auxiliary systems such as radio frequency communicators, auto-senses, etc. Space Marines go through an arduous process where they receive various biogenetically-engineered implants culminating with the implantation of the Black Carapace which allows the Marine a direct and instinctual neural interface with his power armour, transforming it into effectively a second skin. The advanced systems of Space Marine Power Armour also monitor the Marine's biological functions, feeding the collected medical information to the Marine and, if necessary, to the Chapter's Apothecaries when he is wounded. The armour's backpack contains the suit's main power source - a solar power converter and 100 solar cell batteries to store the absorbed solar energy - as well as its environmental and life support system and additional movement stabilizer thrusters.

History and Development
Power Armour has been in use since before the Age of the Imperium, worn by the techno-barbarians that dominated Terra during the Age of Strife. It was also worn by the early genetically-engineered warriors that formed part of the Emperor's retinue during his unification of Terra towards the end of the Age of Strife in the 31st Millennium. In the armour's earliest incarnation, the suit was not fully sealed or life-supporting, this being unnecessary while its use was still confined to Terra. Over the history of the Imperium, Power Armour has developed into many different forms. Need, circumstances and the recovery of new materials and once lost advanced technology has shaped the armour's evolution.

Mark I Thunder Power Armour
The first Power Armour suit type created for the Space Marines was the Mark I Thunder Power Armour. It was developed from the armour worn by the techno-barbarians that plagued Terra near the end of the Age of Strife. It was used during the Emperor’s campaign to retake and unite the Terran solar system before the Great Crusade. It was by no means unique to the first Space Marines - in fact, the techno-barbarian warriors the Emperor fought during the conquest of Terra wore it too, and the Emperor's forces of genetically-enhanced warriors were wearing it even before the first true Space Marines were developed. However, because it was designed with fighting in a terrestrial environment in mind, it is not fully enclosed, with no means to support the wearer in a vacuum. Only the upper body is powered, due in part to the fact that during the Emperor's Conquest of Terra, ranged weapons were difficult to make due to technological constraints, and so a warrior's upper-body strength was his most important asset. It takes its name from the thunder bolt symbol the Emperor used during the Unification Wars on Terra before he adopted the double-headed eagle known as the Imperial Aquila during the Great Crusade. The emblem gives the suit its common name – Thunder Armour. This early armour was produced on a completely local basis. There was no standard design, individual suits varied heavily and their exact designs were often a matter of personal taste. The main part of the armour is the massive powered torso which encloses the chest and arms. Coiled energy cables beneath the armour plating transmit energy from the power pack on the back to the arms, greatly increasing physical strength. Since the fighting on Terra during this period was primarily close-quarters, the strength of a warrior's chest and arms was of paramount importance. The legs of this armour are not powered at all, but are enclosed in tough padded breaches. Although uncommon, the best-equipped warriors sometimes wore armoured greaves and armoured boots.

Mark II Crusade Power Armour
Mark II Power Armour was developed towards the end of the Age of Strife and was used during the dawn of the Imperium by the Space Marines who carried out the Emperor’s Great Crusade to reunite the lost worlds of Mankind in a new Imperium. After the conquest of the main planets of the Solar System by the Emperor's new armies of Space Marines, the Adeptus Mechanicus factories on Mars were set to work constructing a new type of armour for the Emperor's elite Space Marines. This armoured suit is commonly referred to as Crusade Armour, since it was designed with the planned Great Crusade in mind. It was the first fully enclosed suit of Power Armour, making it suitable for the conquest of space. It was designed as a fully enclosed suit with life-sustaining systems that now allowed the Astartes to fight in deep space and on alien worlds with hostile atmospheres or environments. The armour was made up of microscopic circular armour rings fitted under and over each other, making this armour relatively tedious to repair. These precious relics are still used during formal ceremonies and rituals by some Chapters and given to the Chapter's champions as actual battle armour in others.

Mark III Iron Power Armour
As the Great Crusade reached the planets towards the core of the galaxy, some of the worlds encountered were the Squat homeworlds, which were not pleased to find themselves the object of a galactic conquest. The Squats' independent and stubborn nature along with the conditions of the fighting in the Squats' underground cities spurred the creation of this new armour type. High casualties suffered by the Legiones Astartes during the Great Crusade led to the development of the Mark III model of Power Armour, best suited for spacecraft boarding actions and combat in confined subterranean tunnel complexes with little cover. This armour was ideally used by Space Marines when cover was minimal and combat was a matter of a simple frontal assault.

The Mark III was never intended to replace the Mark II armour but instead was a specialised suit to provide heavier protection than the normal Mark II suit when fighting in conditions similar to that found on the Squat homeworlds. It has more frontal protection than the Mark II Armour, but the weight of the rear armour was lessened to compensate. The suit uses a heavy armoured helmet with sloping plates designed to deflect shots to the left and right, thus inspiring its name as the Iron pattern. The helmet inspired the Mark IV and VI helmet designs. The wedge-shaped helmet (designed to deflect incoming fire) formed the basis for the later distinctive Corvus Beak helmet.

Mark IV Maximus Power Armour
As the Great Crusade reached its climax, the Space Marine Legions found their armour wearing out. While some Legions chose to continue local production and maintenance, the Adeptus Mechanicus of Mars designed a new variant, which was to be the Mark IV or Imperial Maximus pattern.

At the Mark IV stage of Power Armour development, Space Marine armour began to take on an appearance recognizable to that of contemporary Power Armour patterns, its primary change being the abandonment of the separate abutting plates of armour in favour of larger, inflexible armour casings incorporating flexible joints. This marginally reduced an Astartes' mobility but was far easier to produce and maintain.

Technical secrets from the Dark Age of Technology recovered on newly conquered worlds during the Great Crusade allowed Mars to develop the more efficient armour, improving the quality of protection and reducing the suit's weight at the same time. Improved armouring of the suit's power cables allowed the main arm and chest supply to be safely relocated to the exterior of the armour, while the use of new materials reduced the size and number of cables.

The Mark IV suit's helmet was a completely new design, the basic shape inspired by the sweeping front of the Mark III. In Mark III and later versions the helmet is no longer fixed, but moves with the wearer's head. This represented the artificers' increasing experience with neural connector gear and the new materials which flooded into the Martian workshops as the Great Crusade progressed.

Mark IV Power Armour was envisioned at the time to be the ultimate and final type of Space Marine armour, able to offer the best protection in a variety of conditions. Many of the Space Marine Legions were entirely or partially re-equipped with it by the start of the Horus Heresy. As a result of its widespread production and use prior to and during the Horus Heresy, Mark IV suits are the most common of the pre-Heresy armour patterns still in service during the 41st Millennium. This pattern of armour is the type of Power Armour still worn by most of the original Chaos Space Marine Traitor Legions, as they usually have access only to the technology they took with them into the Eye of Terror ten millennia ago. However, some Chaos Space Marines mix and match more modern pieces of armour with their ancient Mark II and Mark IV suits to replace damaged portions and those Space Marines who have turned renegade since the Horus Heresy obviously wear the Power Armour that was current to the era when they first turned against the Emperor. Chaos Space Marines often strip more modern pieces to upgrade their armour from the bodies of Loyalist Space Marines killed in battle.

Mark V Heresy Power Armour
The equipping of the Legions with Mark IV armour was only partially complete when the Horus Heresy broke out. Many of the newly-equipped Legions turned against the Imperium while many of the Loyalist Legions possessed only Mark II Power Armour. With the extensive amount of war damage and constantly mobile operations, resupply for the Loyalist Space Marines Legions' damaged equipment was difficult or impossible. This suit of Power Armour was developed by Space Marine Artificers and Techmarines as a solution to the supply problems caused by the Horus Heresy. It was manufactured from the most basic of materials, and it was easy to maintain. Almost all of its users used spikes or rivets to hold the armour layers of plasteel together, and the studs of these spikes became a distinctive marker of this pattern of Power Armour. In time, it became traditional for the studs to be found on the head, lower legs, and left shoulder plate of the armour.

Due to the sub-standard materials used in the construction of this armour variant, it had a tendency to over-heat quickly, and many Space Marines had to endure sub-standard performance by turning down the power output of their backpack to prevent intolerable heat build-ups. The helmet appears to be an early version of the Mark VII helmet, although it is significantly more primitive in its design.

Mark VI Corvus Power Armour
This classic Power Armour variant can be traced back to the time of the Horus Heresy and is still commonly used even in contemporary Space Marine Chapters. It is characterized by the beak-like muzzle on the helmet and a studded auto-reactive shoulder plate on the left shoulder of the armour. The beak or muzzle led fans to nickname this variant "Womble armour" or "Beakie armour", and a dictionary of the Orkish language in the 2nd Edition Ork Codex listed Marines as "beakies". This was the style of the first Space Marine models released by Games Workshop and did not get its Mark VI terminology until after models with the Mark VII styling were released. Models with this style were not part of new releases until the launch of the next range of 25 mm plastic models.

Mark VII Aquila Power Armour
This version of basic Power Armour was also known as Imperator Armour. It is the contemporary variant most commonly used by the Space Marine Chapters of the Imperium. Mark VII armour was developed during the Horus Heresy, and remains in use as the most common form of Power Armour 10,000 standard years later. It represents the final major development of Mark VI armour. While the final battle for Mars was underway with the Traitor Legions during their invasion of the Solar System, the Imperium realised the planet would eventually be lost. Adeptus Mechanicus armour development teams were transferred to Terra to continue their tasks, incorporating their latest work into the armour type that would become the Mark VII. As Mars fell to Horus, the new armour began reaching the Loyalist Space Marines on Terra and Luna. The Mark VII armour is characterised by the grim looking Vox caster (external vocalizer) on the faceplate, and the plastron displaying the Imperial Aquila or the Space Marine honour known as the Imperialis (a winged skull), which has given the armour different names such as Armorum Impetor ("Eagle Armour") or Aquila Armour ("Aquila" being the name of the two-headed eagle which symbolizes the Imperium of Man). As Mark VII is a development of Mark VI, both have a great deal in common, and parts from one pattern of armour are readily interchangeable with parts from the other in Space Marine Armouries.

Mark VIII Errant Power Armour
The Mark VIII pattern is an update to the Aquila Mark VII pattern armour, and is distinguished by a raised collar at the front, and armoured plating for the torso power cables which were vulnerable to weapons fire. The new pattern also addressed the vunerability issues of the Mark VII's neck joint, which had been know to act as a "shell-trap", (a round could hit the chest armour and deflect up into the neck joint). The new collar required a new helmet design, which caused problems for backward compatibility with the earlier helmet types. Mark VIII armour has gone into only limited production thus far, and is seen in limited numbers on the battlefields of the 41st Millennium. Full versions of this armour are almost never seen; however, it is common to find parts of it being used by Space Marine officers, squad leaders and veterans on the battlefield as a sign of their rank. The Mark VIII is not widespread in the Imperium yet and it will take quite a few centuries before the Forge Worlds of the Imperium have brought every Chapter up to the new standard.

Adaptability
One design feature of Power Armour patterns Mark VI through Mark VIII is their extreme ruggedness and high level of adaptability; it is fairly common within most Space Marine Chapters to see a suit combining parts originally created for three or four different patterns of suits, salvaged from dead Battle-Brothers on the battlefield. Mk VII armour, in particular, was created with this simple modularity in mind.

Other Imperial Users
Although Power Armour is most closely associated with the Adeptus Astartes, it is also used by the Sisters of Battle, the Grey Knights and some more martial-minded Inquisitors of all three Ordos. However, the Sisters of Battle and Inquisitors who use power armour do not possess the black carapace implant, and so can not be directly linked to the suit's advanced movement enhancement and fire control systems in the way Space Marines are, which decreases the armour's effectiveness. Some members of the Adeptus Mechanicus, the Machine Cult, use power armor. Engineseers of the Imperial Guard use it to protect them from enemy fire as they tend to the machine spirit of Guard vehicles.

Aegis Armour
Main article: Grey Knights Specialist Equipment The Grey Knights Space Marines who serve the Inquisition's Ordo Malleus as its Chamber Militant wear Aegis Armour, power armour that is incredibly well crafted, anointed and inscribed with prayers and wards, ritually consecrated and psychically charged to protect them from the psychic powers and sorcery of Chaos-worshipping heretics and daemons. The suits are generally based on components from Mark VI, VII and VIII Power Armour designs, with a modified helmet design that is reminiscent of the Mark III.

Adepta Sororitas Power Armour
The Militant Orders of the Adepta Sororitas, better known as the Sisters of Battle, use a lighter, less bulky version of Power Armour. This armour does not increase the strength of the wearer to match that of the Space Marines, but does provide the same level of ballistic and energy pulse protection.

Space Wolves Runic Armour
The Space Wolves Space Marines grant valiant members of their Chapter specially crafted suits of Power Armour inscribed with runes of protection by the Space Wolf Rune Priests. These provide the wearer with a defence against psychic attacks. This armour is created by the Iron Priests and codified by the Adeptus Mechanicus as the Mark XII Lupio pattern.

Chaos Power Armour
At the time of the Horus Heresy in the 31st Millennium, Mark II Crusade pattern Power Armour had all but disappeared from the Astartes Legions, replaced by the much improved Mark IV Maximus pattern, with the exception of those Legions still fighting on the Eastern Fringe of the galaxy. Even so, during the fierce battles to come both sides were forced to reinstate older marks of Power Armour to replace their losses as well scavenging and cannibalising armour from the battlefields. The armour of the Traitor Legions that fled into the Eye of Terror still reflects these turbulent times, often featuring distinctive studded and rivetted plasteel plates rather than the smooth ceramite of the later designs. Exposed power cables remain a common feature of Chaos Power Armour and many Chaos Space Marines individualise their armour with crests, horns, skulls and chains. Quite often, a Chaos Space Marine's Power Armour will have been altered by long exposure to the Warp. It may have sprouted spines or bony ridges, be covered in a layer of scales, or flicker with arcane and corsucating energies. The competition for new or replacement armour parts is fierce among the Traitor Legions. Chaos Space Marines who have only recently become Renegades may have armour that has changed hardly at all from their former Chapter's standard livery, except for the deliberate defilement or removal of badges or symbols of allegiance to the Emperor of Mankind. Some Chaos Space Marines thus possess suits of the advanced Mark VIII Errant pattern armour, which is much coveted by other Traitor Marines and can earn the wearer greater prestige among the Forces of Chaos.