Imperium of Man

The Imperium of Man is a galaxy-spanning interstellar human empire, the ultimate authority for the majority of the human race in the Milky Way Galaxy. However, there are other humanoid species classified in the Imperium, mainly mutant offshoots of base-line humans such as the Ogryn, Ratlings and Squats. The founder and ruler of the Imperium is the god-like Emperor of Mankind, the most powerful human psychic born to date. Founding the Imperium over ten thousand years ago, the Emperor continues, at least nominally, to lead it as both political master and primary religious figure.

The Imperium is the largest and currently most powerful political entity in the galaxy, consisting of at least a million settled worlds dispersed across most of the Milky Way Galaxy. Consequently, an Imperial planet might be separated from its closest neighbor by hundreds or thousands of light years. As a stellar empire, the size of the Imperium cannot be measured in terms of contiguous territory, but only in the number of planetary systems under its control.

Several alien species and forces (the Forces of Chaos, the Tyranids, the Eldar, the Dark Eldar, the Orks, the Tau, and the Necrons) challenge the supremacy of the Imperium and humanity's predominant place in the galaxy. From within its own creaking edifice, the Imperium is threatened more insidiously by rebellion, mutation, dangerous psykers and subversive Chaos cults.

Without the admittedly authoritarian and often harsh protection of the Imperium, mankind as a whole would fall prey to the countless perils that threaten it and likely long ago have become extinct.

History of the Imperium
The Imperium was founded by the Emperor of Mankind, also called "The Immortal Emperor", "The God-Emperor", and the "Master of Mankind", at the end of the Age of Strife, around the year 29,000 A.D. The Emperor, an immortal being born about 8000 BC in central Anatolia on Earth, was the collective reincarnation of all the human shamans who had possessed psychic abilities. Imbued with their combined psychic, physical and intellectual power, he helped humanity as a whole survive and prosper through the long millennia. In various eras of human history he intervened through various personas to guide humankind, though such interventions were apparently brief and shrouded in mystery. At the closing of the Age of Strife he finally took a direct, public, and permanent role in the affairs of humankind.

Prehistory
The Age of Strife was a very long period of anarchy, war, and destructive technological regression which brought humanity to the brink of extinction - and reversed the highly advanced scientific and technological discoveries made during the Dark Age of Technology that preceded it. It was caused by the negative psychic and physical effects of vicious Warp storms raging through large portions of the Galaxy, "ripples" of the explosive force of the birth of the Chaos God Slaanesh. One result of the storms was the impossibility of faster-than-light travel, and the subsequent isolation of worlds and systems separated by multi-light-year distances. Human civilization in the previously colonized galaxy fragmented, and where it survived, it took wildly different forms. On Earth, the planetary economy collapsed and social order broke down. Wars, rebellion, and disease were rampant. Knowledge accumulated in the previous millenia was lost or forgotten, and a slow descent to barbarity seemed inevitable. Brutal warlords emerged, carving large swaths of territory as their fiefdoms and imposing an uneasy peace that was frequently interrupted by feudal conflicts. That was the setting around AD 29000, when the man that would be known as the Emperor re-entered the affairs of man.

The Great Crusade
The Emperor sensed that the Warp storms that had marked the Age of Strife were starting to subside, and after unifying the Earth under his rule through diplomacy and the waging of the brutal Unification Wars against the techno-barbarians tribes that ruled vast swathes of the Earth's surface, he secured the allegiance to the new Imperium of the Cult Mechanicus of Mars, the scientific research installations and spacedocks of Luna, and the Martian factories and tech adepts. The Emperor then began a vast new military campaign to reunite mankind, dispersed throughout the galaxy, under his rule. This marked the beginning of the period that would be known as the Age of the Imperium. A vast fleet of starships was built, with which the Emperor's armies undertook a Great Crusade to reunite all of humanity across the galaxy, an effort that lasted around two centuries, before being cut short.

During this more than two-hundred-year-long military campaign, the Emperor employed his most potent military units, the Space Marine Legions, lead by their gene-fathers, the Primarchs, who were his own genetically engineered sons. These Astartes Legions, combined with the might of the Imperial Army (which was later separated into the Imperial Guard and the Imperial Navy), reunited thousands upon thousands of human worlds into one interstellar civilization, in the name, and under the rule of, the Emperor and the Imperium of Man. The Great Crusade was ended abruptly by the corruption and treachery of the Imperial Warmaster Horus, Primarch of the Sons of Horus Space Marine Legion. Horus instigated the terrible Horus Heresy rebellion against the Emperor and convinced almost one-half of the Imperium's military forces to turn Traitor, unleashing the greatest conflict mankind had ever known upon the galaxy.

The Horus Heresy
The Horus Heresy was fought across the galaxy. Horus, seeking to achieve a swift and decisive victory over the Emperor after pledging his soul to the service of the Ruinous Powers of the Warp, lead traitor Space Marine forces directly to Terra. In a final decisive battle between the Emperor and Horus, the Warmaster was slain, leading to the break up of the rebellion. However, the Master of Mankind was himself mortally wounded during the battle, which took place on Horus' Chaos-twisted flagship in orbit above Terra. The Emperor's body was recovered by Primarch Rogal Dorn and according to his last instructions, he was placed on the life-preserving Golden Throne, a potent cybernetic life-support system, where, for over ten thousand years, he has remained immobile. Though physically a broken, dying carcass incapable of movement and presumably unable to communicate with the outside world, the Emperor's psychic will, almost omnipotent, extends through the Immaterium across the million worlds of the Imperium, produces the psychic beacon of the Astronomican that is used by all Imperial starships to travel through the Warp, soul-binds weaker psychic humans by leeching the souls from their bodies to sustain his psychic presence, and struggles against the daemons of the Warp. In all this, the Emperor endures constant endless agony only through sheer undying will, and thanks to the sustenance that the souls of the sacrificed psykers provide. By the numberless masses of humanity he is worshipped as both a god and their only savior.

The Imperium after the Heresy
Most of the Imperium is at M42 a relatively dystopic society by the standards of twenty-first century humanity. The events of the Horus Heresy destroyed untold resources in the budding Imperium, but more importantly, starting with the Emperor himself, claimed some of its best warriors, technocrats, administrators and diplomats - fallen either in battle or to Chaos. But perhaps the most significant consequence seems to have been that like the Emperor, the Imperium itself entered into a form of slowly decaying stasis, while Chaos and other enemies are ascendant.

It is known that the period immediately following the Heresy was one of near-anarchy, and that the continuity of the Imperium was not assured. Roboute Guilliman, the Primarch of the Ultramarines was one of those credited with taking decisive action that kept the Imperium together, possibly with the help of other Loyalist forces and of newly-created Imperial Organizations such as the Inquisition and others (it is known that at least one Assasin Temple was already operating with Imperial Sanction, and had succesfully liquidated Konrad Curze). Ironically, while the Imperium survived, it also seems to be fulfilling predictions or prophesies made about its future by a variety of Chaos enemies, traitors, and more neutral or potentially sympathetic observers. Supreme among such ironic twists is the deification of the Emperor and attendant creation of the Ecclesiarchy. The Emperor's express concern and one of the pillars of pre-Heresy Imperial Truth enunciated during the Great Crusade was the elimination of superstition, of belief in supernatural powers, gods, and religion. It is worth noting that one of the ploys used by the Ruinous Powers to turn Horus traitor were uncannily accurate visions of the post-Heresy Imperium.

Another measure of stagnation has been the lack of real technological progress and a fear of unknown or ancient technology that sometimes borders on superstition. It seems that the last major era of human technological advancement was the era of discoveries and technological applications made during the planning and execution of the Great Crusade.

Political structure of the Imperium
The Imperium is still nominally ruled by the Emperor of Mankind as an absolute monarch. However, since his ascension to the Golden Throne, the duty of actual high-level governing of the Imperium falls to the Senatorum Imperialis - the Imperial Senate, formed by the twelve High Lords of Terra. The identities and responsibilities of these High Lords may vary, as individuals inevitably die and their influence grows and wanes, but its members are always the leaders and representatives of the most powerful Imperial organizations.

Ultimately, the High Lords are in control of the Imperium as a whole, and are responsible for maintaining the functioning of the Imperium through the Adeptus Terra and the Imperial Commanders who govern each Imperial world. However it is unfeasible to maintain a completely centralized government over such vast interstellar distances, even with faster-than-light travel and telepathic communication. This means that the Imperium is structured like a confederacy, with the planetary rulers acting as feudal lords subject to the higher authority of the Adeptus Terra and responsible for providing men to the Imperial Guard, but largely free to run their worlds day-to-day as they see fit. Therefore, many Imperial worlds are left to fend for themselves without any direct involvement of the central government save in a time of crisis.

The flow of information in the Imperium is tightly controlled, with several Imperial bodies withholding information (chief among these is the Inquisition, an ever-present Censor) or engaging in misinformation and propaganda (such as the Ecclesiarchy among others). Other Organizations zealously protect information that could be used for the benefit of the Imperium as a whole, such as the widespread withholding of technological information by the Adeptus Mechanicus. The censorship has been justified by the terrible and dangerous nature of some of this information, and by the sheer immensity of the task of governing the Imperium.

The stellar empire is so massive and sprawling that it includes a wild variety of diverse worlds, ranging from jungles inhabited by Neolithic savages to polluted ecumenopoleis, great cities ("hives") that in some cases cover entire planets. For example Gudrun, a world mentioned in the Eisenhorn Trilogy by Dan Abnett, is similar to an idyllic 18th century Merry England, with stately manors controlling vast estates of rolling green hills studded with small villages, while Catachan is a hellish Death World filled with carnivorous plants (see Planets of Warhammer 40,000).

Imperial organizations
Most of the organizations comprising the Imperium's government are divisions of the vast Adeptus Terra (the Priesthood of Earth). There are countless divisions, and some are so secretive their existence is known only to a few. Perhaps the most well-known of the "secret" organizations is the Inquisition, while others are known only to the higher Imperial echelons, one example being the Officio Assassinorum, the organization tasked (by the will of the Emperor) with carrying out assassinations deemed necessary to the Imperium. Other organizations are secret enough that nothing other than the fact that they exist is known, such as the Officio Sabatorum and the Templars Psykologis.

The most important and well-known Imperial organizations include:


 * The Adeptus Administratum, responsible for the administrative functions of the entire Imperium, is the largest division, numbering countless scribes and petty officials. It administrates the Imperium at every level, assessing tithes and taxes, conducting population censuses, recording and planning. It consists of innumerable subdivisions, offices and departments.
 * The Departmento Munitorium, itself a department of the Adeptus Administratum, which is responsible for administering and supplying the Imperial Guard across the galaxy.
 * Adeptus Astra Telepathica, the Imperium's network of Astropaths, the sanctioned psykers who are responsible for transmitting faster-than-light messages through the Immaterium and maintaining mankind's fragile network of interstellar communications.
 * Adeptus Astronomica, responsible for maintaining the Astronomican which is used by the mutant psykers known as Navigators to navigate all Imperial starships, military or civilian, through the Warp.
 * Navis Nobilite, the aristocracy of Navigators who pilot all Imperial vessels through the dangers of the Warp.
 * Adeptus Mechanicus, the priesthood of technicians and scientists dedicated to the Machine Cult who build and maintain all Imperial equipment, vehicles, starships, and weapons of war.
 * Adeptus Custodes, guardians of the Emperor's physical form, essentially his bodyguards and the greatest warriors of the Imperium.
 * Adeptus Arbites, a galactic police force which enforces the Lex Imperia - the Imperial law - and have the right to serve as judge, jury and executioners on every Imperial world.
 * Officio Assassinorum, the most covert of all the known Imperial agencies, the assassins are responsible for removing the key leaders of an enemy of the Imperium - whether that enemy is a threat from without or within.
 * The Imperial Inquisition, the secret police force of the Imperium whose agents serve as jack-of-all-trades troubleshooters for any potential problems that might threaten the safety of humanity; they are responsible for investigating any potential threat to mankind or the Imperium. It is divided into three major orders: the Ordo Malleus, which hunts daemons and those corrupted by the Ruinous Powers of Chaos; the Ordo Xenos which eliminates the threat that other intelligent alien civilizations present to humanity's rule of the galaxy; and the Ordo Hereticus which hunts down mutants, heretics of the Imperial Cult, and all those who would threaten the Imperium from within. The Inquisition's agents necessarily exist and operate beyond the control of the Adeptus Terra, since part of the Inquisition's role involves rooting out corruption and gross incompetence from within the highest levels of the Imperium itself. Inquisitors ultimately answer only to the Emperor and to themselves.
 * Adeptus Ministorum, the Imperial Cult which maintains control of the Imperial Creed and the galaxy-spanning faith of the God-Emperor of Mankind.

The military forces of the Imperium include: Other forces include Inquisition Storm Troopers and Adeptus Mechanicus troops such as the TechGuard, the Skitarii and squads of Combat Servitors.
 * Imperial Guard
 * Adeptus Astartes (the Space Marines, including the Grey Knights and Deathwatch, who serve as the Chambers Militant of the Inquisition's Ordo Malleus and Ordo Xenos, respectively)
 * Collegia Titanica (War Machine division of the Adeptus Mechanicus)
 * Sisters of Battle (Adepta Sororitas) (Division of the Ecclesiarchy. Select Orders serve as Chamber Militant of Ordo Hereticus)
 * Imperial Navy

The Imperial Domain
The Imperial Domain is in essense defined by the reach of the psychic beacon of the Astronomican, which has a range of approximately 50000 light years. The Imperium proper could thus be thought of as a sphere whose center lies at Terra's Sol (solar) System, and whose radius is about 50000 light years wide. However, as a practical matter, agents and agencies of the Imperium (along with "unofficial" representatives of the Imperium - such as Rogue Traders - who often work in tandem with the goals of the Imperium) carry on its affairs and expand its influence beyond that limit.

The disparate and widespread nature of Imperial territory, with its millions of star systems and worlds, means that a strongly centralized government would be unfeasible.

The Imperium of Man divides the galaxy into five administrative zones called Segmentae Majoris:


 * Segmentum Solar, centered on the Sol System.
 * Segmentum Pacificus, the galactic "west."
 * Segmentum Obscurus, a region to the galactic "east" of Terra that has been heavily fortified by the Imperial Navy and the Imperial Guard due to the dangers posed by this Segmentum's most infamous element, the Eye of Terror. This is a vast Warp rift where the Immaterium actually intrudes upon material space - as do the Chaos Space Marine Traitor Legions and the daemons of the Ruinous Powers themselves.
 * Segmentum Tempestus, the galactic "south."
 * Segmentum Ultima, the largest province of all in the Imperium, located to the galactic "north" of Terra; its furthest extents are beyond even the range of the Astronomican in space still unexplored by humanity.

The Segmentae are the primary administrative divisions of the Imperium. Each is divided into sectors, which are areas of three-dimensional space. The sectors in turn consist of sub-sectors, each containing a number of individual star systems. These spatial divisions and subdivisions are also levels of the administrative hierarchy.

Each Segmentum Commander oversees his Sector Commanders, who in turn oversee Sub-sector Commanders, who in their turn oversee the individual Planetary Governors. The higher ranks in this system are usually combined with a basic planetary governorship as well as interplanetary duties. This system is the means by which the Imperium maintains control of the separate planets that comprise it.

Planetary administration
Because of the distances involved and the unstable nature of Warp communication, Planetary Governors generally operate very autonomously. This allows quite a lot of variation in the regional governments of the Imperium. Some governorships are hereditary, but it is also possible for a planet to have an elected Planetary Governor, a tyrant Governor who rules solely by force of his personal arms, or anything in between. So long as the Governor fulfills his duties to the broader Imperium, his rule will generally be accepted by the higher authorities with little or no interference.

A rare few Planetary Governors preside over feral or medieval worlds where the Imperium has not, for whatever reason, seen fit to introduce modern technology. These Governors are often isolated from their subjects, sometimes even living on orbital installations, only interfering to control mutation, Chaos incursions, Ork invasions and rogue psykers, as well as to collect the modest tithes in men for the Imperial Guard and psykers that these planets provide.

The Imperial duties of a Planetary Governor include paying the planetary tithe to the Administratum, controlling psykers, mutation and heresy among the population, defending the planet and putting down rebellions against the local government (and thus against the Imperium).

A serious responsibility is the maintenance of an adequate planetary defence force capable of defending the planet in the event of an invasion. The Planetary Defence Forces (abbreviated to PDF) are expected to defeat attacks from minor foes, and in the case of major invasions to hold out until reinforcements arrive, which could take a period of months, years or even decades.

A relatively small number of Imperial worlds are not ruled by a Planetary Governor, but are directly overseen by an alternate organisation such as the Adeptus Terra, the Ecclesiarchy, an Imperial Commander of the Imperial Guard or a Chapter of the Space Marines. These planets include the Forge Worlds of the Adeptus Mechanicus, whose inhabitants toil without pause to manufacture the weapons of the Emperor's armies (including Mars, Gryphonne IV and Fortis Binary), the Cardinal Worlds of the Ecclesiarchy, which are given entirely over to education of the priesthood and worship of the Emperor (Ignatius Cardinal, Ophelia VII), and the Space Marine Chapter home planets, such as Fenris, Macragge, Baal, or Medusa.

Rebellion
The Imperial creed maintains that all of humanity must be brought and kept within the Imperium where men and women can benefit from the rule of the Emperor. Several Imperial organizations are permanently occupied with suppressing any possibility of rebellion before it has a chance of developing. The common worship of the God-Emperor holds mankind together and instills loyalty towards the Imperium. Rebellions and uprisings on Imperial planets nonetheless remain a constant problem. The nature and causes of a rebellion can fall into several categories: the government of an Imperial world may decide to secede from the Imperium; a popular uprising may attempt to overthrow the local Imperial government; in the most insidious of cases the rebellion may be brought about by alien or Chaos influence. In the more prosaic cases however, a government established through rebellion is not necessarily opposed by the Imperium, so long as it accedes fully to Imperial authority and pays its tithes to Terra.

Besides outright war, there are many ways a rebellious world may be brought back into the Imperium. With the existence of its more secretive organizations like the Inquisition, the Imperium is fully capable of carrying out covert methods of restoring Imperial rule, including assassination, popular agitation, economic sabotage and terrorism. Sometimes a rebellion can be subdued by the removal of a single individual. Pro-Imperial groups or other anti-government forces can be infiltrated or supported.

Imperial Languages
Low Gothic is the common tongue of the Imperium, spoken on most Imperial planets as a first or second language. Imperial worlds have inevitably developed their own often highly variant dialects of Low Gothic over time. High Gothic (represented as a form of Latinised English) dates from the last time humanity was united across interstellar distances during the Dark Age of Technology (long before the Age of the Imperium), and is used solely as a hieratic tongue by the divisions of the Adeptus Terra, the Inquisition and the Ecclesiarchy.

Imperial Calendar
The Imperium of Man uses a special Imperial Dating System derived from the original Gregorian Calendar of Old Earth that denotes the current year by the notation &lt;year of the millennium&gt;.M&lt;millennium&gt;. For example, the year 40,999 AD would be represented as 999.M41, while 41,002 would be 002.M42 and the year 2010 would be 010.M3. However, the year 41,000 AD would be 000.M41, since the new millennium starts at the year 001 and has no Year 0.

Other Science Fiction Influences on the Imperium of Man
The Imperium itself, in keeping with the dystopian themes of Warhammer 40,000, is a highly oppressive techno-theocracy obviously influenced by the Padishah Empire found in Frank Herbert's Dune. It also closely resembles Isaac Asimov's Galactic Empire in the Foundation series, with millions of star systems only loosely connected with the governing center, where technology is becoming a myth rather than a science, with extreme persecution of those questioning the morality or validity of the endless conflicts and divine rule of the Emperor.