Imperium of Man

"The martyr's grave is the keystone of the Imperium." -- The Liber Imperialis

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, and is ruled by the living God who is known as the Emperor of Mankind. However, there are other humanoid species classified as Imperial citizens, mainly mutant offshoots of genetic base-line humans who are known as Abhumans and include such human sub-races as the Ogryns, Ratlings and Squats. The founder and ruler of the Imperium is the god-like Emperor of Mankind, the most powerful human psyker ever born. The Emperor founded the Imperium over 10,000 Terran years ago, and the Emperor continues, at least nominally, to rule the Imperium as both its political master and its primary religious figure, though his badly damaged body is interred within the cybernetic life support mechanisms of the arcane device known as the Golden Throne. Because of this, the Emperor is incapable of interacting with others on a day-to-day basis.

The Imperium of Man is a war-torn empire, teetering on the brink of collapse. For 10,000 Terran years it has been ruled by the deathless Emperor, a being of incredible power, to whom thousands of souls are sacrificed daily. The peoples of the Imperium live in a place where Daemons are real, mutation is frequent and death is a constant companion. To be alive in the 41st Millennium is to know that the universe is a terrifying and hostile place. It is a place where you are but one amongst billions and, no matter how heroic your death, you will not be missed. A truly vast domain, the Imperium is spread amongst the many stars of the galaxy. Its territories encompass untold millions of stars and countless more human lives. In its name, terrible wars are fought and desperate sacrifices made, yet even this river of carnage and blood is a small price to pay, for the Imperium is the guardian of Mankind. Were it to pass into nothingness, so too would the human race, destroyed by enemies uncountable, to the braying laughter of the Dark Gods.

The Imperium is the largest and currently most powerful political entity in the galaxy, consisting of at least 1,000,000 human-settled worlds dispersed across most of the Milky Way Galaxy. Consequently, an Imperial planet might be separated from its closest neighbour by hundreds or even 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 and increasingly stagnat and repressive edifice, the Imperium is threatened more insidiously by rebellion, mutation, dangerous psykers and subversive Chaos Cults. However, despite its myriad problems, without the admittedly authoritarian and often harsh protection of the Imperium, Mankind as a whole would have fallen prey to the countless perils that threaten it. Without the Imperium and Mankind's faith in the Emperor who guides it, the human race would have become extinct long ago.

History
The Imperium was founded by the Emperor of Mankind, also called "The God-Emperor" and the "Master of Mankind", at the end of the Age of Strife, in the 30th Millennium. The Emperor, an immortal being born around the year 8000 BC in central Anatolia on Old Earth, was the collective reincarnation of all the human shamans who possessed true psychic abilities during the Paleolithic and Neolithic Ages. Imbued with their combined psychic, physical and intellectual power, the Emperor was born an immortal being of unparalleled physical strength, psychic ability, charisma and intellect. The Emperor helped humanity as a whole survive and prosper through the long millennia. In various eras of human history he intervened through various personas, some of them well-known historical personages, to guide Mankind, though such interventions were always brief and shrouded in legend and historical mystery. At the end of the Age of Strife the man who would become the Emperor finally took a direct, public, and permanent role in shaping the future of humanity, believing that the damage done to the human race by 5,000 years of terror, isolation and violence could not be reversed unless he openly guided humanity as its leader. As such, he shed all his prior identities and simply revealed himself in the 30th Millennium on Terra as the Emperor of Mankind, determined to unite the entire species under his stern but benevolent rule and replace superstition, fear, poverty and intolerance with reason, science, progress and hope.

Prehistory
The Age of Strife, also sometimes called Old Night, was a 5,000-year-long period of anarchy, war, and destructive technological regression from the 25th to the 30th Millenniums that brought Mankind to the brink of extinction - and reversed the highly advanced scientific and technological discoveries made by the galaxy-spanning interstellar human civilisation of the Dark Age of Technology that had preceded it. The Age of Strife was caused by the negative psychic and physical effects of the vicious Warp Storms that ravaged large portions of the galaxy beginning in the 25th Millennium, which were the "ripples" in realspace of the psychic gestation of the new Chaos God Slaanesh in the Immaterium. Slaanesh was forming within the Warp as a result of the growing hedonism and utter excess of the ancient Eldar empire in the millennia before its Fall. One result of the Warp Storms was the impossibility of faster-than-light travel or telepathic interstellar communication through the ravaged currents of the Warp, which led to the subsequent isolation of human colony worlds and star systems separated by multi-light-year distances. Human civilisation in the colonised portions of the galaxy fragmented, and where it survived, it took on wildly different forms. On Earth, the planetary economy collapsed with the loss of interstellar trade and communication with the rest of humanity and the social order broke down. Wars, rebellion, and disease were rampant. Vast swathes of the advanced scientific and technical knowledge accumulated in the previous millennia was lost or forgotten, and a slow descent into barbarism seemed inevitable. Brutal warlords emerged, who carved out new kingdoms to serve as their fiefdoms. The emergence of these often brutal neo-feudal kingdoms, the new nations of the people later termed "techno-barbarians" by Imperial historians, imposed an uneasy peace on the Earth that was frequently interrupted by feudal conflicts. The human race seemed on the brink of extinction at the start of the 30th Millennium, when the man who would become known as the Emperor of Mankind once more inserted himself into the affairs of humanity.

The Great Crusade
The Emperor sensed that the Warp Storms that had marked the Age of Strife were starting to subside, and that this offered an opportunity for Mankind to reunite in pursuit of a new Golden Age. The Emperor first emerged to unify all the techno-barbarian states of Terra under his rule through either diplomacy or the waging of the brutal military campaigns later called the Unification Wars against the techno-barbarians tribes that ruled vast swathes of the Earth's surface. These wars were waged with soldiers who had been genetically-engineered by the Emperor's genius to be faster and stronger than base-line humans. Such warriors would provide the early foundation from which he would later decide to create the Primarchs and and the Space Marines. After conquering the last of the independent techno-barbarian states of Terra, the Emperor also secured the allegiance of the Cult Mechanicus of Mars who controlled the most advanced remaining industrial fabrication and scientific research facilities in the human-settled galaxy and the scientific research installations and spacedocks of Luna. These three factions, Terra, Mars and Luna, signed the Treaty of Mars that created a new government, the Imperium of Man, marrying the Terran military might of the Emperor with the industrial strength of Mars and the Mechanicus. Now possessed of the needed manpower and materiel to make his dream a reality, the Emperor mobilised the resources of Terra and Mars to launch a vast new military campaign intended to reunite the whole of Mankind, dispersed across the galaxy, under his rule. This campaign, the Great Crusade, marked the beginning of the period that would be known as the Age of the Imperium. A vast fleet of starships was built in orbit of Mars, with which the Emperor's armies set out to reconquer the galaxy for Mankind.

But to lead his campaign, the Emperor had used his advanced knowledge of genetic engineering and the psychic arts to create the Primarchs, 20 superhuman military commanders possessed of preternatural physical, mental and social attribtues who had been created through the fusion of his genetic material with the power of the Warp. The Emperor had known that the greatest foe of his plans to reunite the human race and bring Order to the galaxy would be the Ruinous Powers of Chaos and their daemonic servants. He had sought to protect his gestating Primarchs from the Dark Gods while they grew in their gestation capsules in the Emperor's secret laboratories deep beneath the Himalayan Mountains, but the Chaos Gods saw through all his wards and protections. They opened a Warp portal in the Emperor's laboratory and stole the infant Primarchs away from Terra, scattering them across the galaxy and tainting many of them with the power of Chaos.

But the Emperor would not be deterred by this tragedy. Using what remained of the Primarchs' genetic material, he proceeded to transform ordinary Terran men into a new corps of superhuman warriors who would lead Mankind back out into the stellar void. These men were the Emperor's Astartes, the Space Marine Legions, and they were men who knew no fear.

During the 200 years that the Great Crusade spread the Imperium across the galaxy, the Emperor slowly made contact once more with all of his scattered gene-sons, the Primarchs, and to each he gave command of the Space Marine Legion that had been created from that Primarch's specific genome. Horus was the first of the Primarchs to be rediscovered, on the barren Mining World of Cthonia only a few light years from Terra itself. Horus campaigned with the Emperor for 30 Terran years before the next of the Primarchs was recovered, and during that time the two developed a special bond, the deep affection between a father and his favoured son. The Astartes Legions, combined with the might of the Imperial Army (which was later separated into the Imperial Guard and the Imperial Navy after the Horus Heresy), reunited thousands upon thousands of human worlds into one interstellar civilisation, in the name, and under the rule of, the Emperor and the Imperium of Man. But the Great Crusade was ended abruptly by the corruption and treachery of the Imperial Warmaster Horus, who was both the Primarch of the Sons of Horus Space Marine Legion and the overall commander of the Great Crusade, an honour that had been granted to him by the Emperor, who had sought to leave the campaign so that he might return to Terra and oversee a project intended to open up the Eldar Webway to human use.

But Horus and many of the other Primarchs deeply resented the Emperor's absence from the Great Crusade and were even more disturbed by his attempts to replace the direct rule of the Imperium by the Emperor and his Primarchs with a bureaucracy of normal humans. Riven by jealousy and ambition, Horus proved to be easy prey for the tempations of the Chaos Gods, who falsely convinced the Warmaster that the Emperor had intended all along to simply use the Primarchs and the rest of humanity to transform himself into a God. Enraged at this notion, the Ruinous Powers then promised Horus their support in his bid to seize the Imperium for himself. Horus ultimately convinced 9 other Primarchs and their Space Marine Legions to join his cause and serve Chaos. He instigated the terrible Horus Heresy rebellion against the Emperor and eventually one-half of the Imperium's vast military forces, as well as elements of the Adeptus Mechanicus, rallied to the Traitor's cause, unleashing the greatest conflict Mankind had ever known upon an unsuspecting galaxy.

The Horus Heresy
The Horus Heresy was fought across the galaxy for more than 7 years, beginning with the terrible Battle of Istvaan III where Horus cleansed 4 of his Traitor Legions of their remaining Loyalist elements and the Drop Site Massacre of Istvaan V, where Horus and his Traitor Legions slaughtered three whole Loyalist Space Marine Legions with the worst kind of treachery. 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 the Traitor forces directly to Terra over the next 7 years, slaughtering billions of people and destroying much of what the Emperor had built over the last 2 centuries. In a final decisive battle between the Emperor and Horus at the end of the great Battle of Terra, the Warmaster was slain, leading to the end of the rebellion when the Forces of Chaos naturally began to turn on one another without Horus' ambition, titanic charisma and influence to keep them united in pursuit of a single goal. Over the next several years, the Traitor Legions and their Chaotic allies slowly withdrew from Imoperial space, eventually fleeing Imperial pursuit into the great Warp rift in the Segmentum Obscurus known as the Eye of Terror.

However, the Master of Mankind was himself mortally wounded during the battle, which took place on Horus' Chaos-twisted Battle Barge, the Vengeful Spirit, in orbit above Terra. The Emperor's body was recovered by the Primarch Rogal Dorn of the Imperial Fists Legion and according to his last instructions, the Emperor was placed on the life-preserving Golden Throne, the arcane artefact from the Dark Age of Technology that served as both a psychic amplifier and a potent cybernetic life-support system that the Emperor originally intended to use to create a portal into the Webway. For over 10,000 years now, the Emperor has remained immobile on the Golden Throne. Though physically a broken, dying carcass incapable of movement and unable to communicate normally with the outside world save through the rare telepathic contact and the Emperor's Tarot, the Emperor's psychic will, almost omnipotent, extends through the Immaterium across the million worlds of the Imperium. It produces the psychic beacon of the Astronomican that is used by all Imperial starships to travel through the Warp, soul-binds weaker psychic humans to make them useful Sanctioned Psykers of the Imperium while leeching the lives from other psykers to sustain his psychic presence, and struggles against the encroaching daemons of the Warp, protecting Mankind from their realspace predations. In all this, the Emperor endures the constant agony of his dying body only through a sheer exercise of will, and the sustenance that the life forces of the sacrificed psykers provide. Yet the masses of humanity worship the Emperor as both a God and their only saviour. It is an article of faith in the Imperial Cult that against all the threats faced by the human race, only the Emperor protects...

Imperial Stagnation
The Imperium of Man at the end of the 41st Millennium is a dystopic society by the standards of the men and women of the 21st Century. The unexpected horrors of the Horus Heresy fatally weakened the nascent Imperium, but more importantly, starting with the Emperor himself, claimed some of its best warriors, technocrats, administrators and diplomats - who fell either in battle with the Traitor Legions or were corrupted by Chaos themselves. But perhaps the most significant consequence seems to have been that like the Emperor, the Imperium itself entered a slowly decaying stasis, while Chaos and the Imperium's myriad xenos 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 organisations such as the Inquisition and the Officio Assassinorum (it is known that at least one Assasin Temple was already operating with Imperial sanction, and had succesfully assassinated Konrad Curze, the Primarch of the Night Lords Traitor Legion). Ironically, while the Imperium survived, it also seems to be fulfilling predictions or prophesies made about its future by a variety of Chaotic enemies, Traitors, and more neutral or potentially sympathetic observers like the Eldar. Supreme among such ironic twists is the deification of the Emperor and the attendant creation of the Ecclesiarchy, the galaxy-wide church dedicated to the Imperial Creed that teaches that the Emperor is the God of Mankind. The Emperor's express purpose and one of the pillars of the pre-Heresy Imperial doctrine known as the Imperial Truth that was spread by the Imperial forces during the Great Crusade was the elimination of superstition and of belief in supernatural powers, gods, and religion and the promotion of reason and science. It is worth noting that among the ploys used by the Ruinous Powers to turn Horus to their service were uncannily accurate visions of the post-Heresy Imperium in which the Emperor and his Loyalist Primarchs were worshiped by the Imperial masses as a God and his saints, respectively. Of course, unknown to Horus, this was a future caused by his actions, not prevented by them.

Another measure of the Imperium's stagnation has been the lack of real technological progress over the last 10,000 Terran years and a fear of unknown or ancient technology that sometimes borders on irrational 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.

In short, the Imperium has become a repressive regime marked by extreme levels of superstition, political repression, religious intolerance, bureaucratisation, economic stagnation, technological regression and inequality. Corruption and injustice are rampant and human life is increasingly worth very little in a galaxy teeming with literally trillions of people. But though the Imperium is repressive and stagnant, it is also the only thing holding the enemies of Mankind at bay. Many in the highest levels of the Imperium know that it must reform if it is to survive, but they fear that the cure might very well kill the patient. And in small pockets of the Imperium there are men and women willing to shoulder the burden of making their small corner of the universe a better place for all by shouldering the responsibilities and the burdens of heroes.

But recently, in 999.M41, the Adeptus Mechanicus has secretly reported to the High Lords of Terra that in addition to all the other problems besetting the Imperium, the mechanisms of the Golden Throne are malfunctioning and they no longer possess the necessary knowledge to repair them. Whether the nobles of the Imperium like it or not, a terrible change is coming...

The Feudal Order
The Imperium covers a wide area of galactic space, sprawling over countless worlds. There are few universal constants amongst these wildly varying planets. Culture, language and even the human form appear in seemingly infinite variation across the galaxy. One of the few constants (at least amongst those worlds of the Imperium that are aware of its existence) is the network of Imperial feudal obligation and responsibility. Each Imperial planet owes fealty to a Planetary Governor. This individual in turn renders to the Imperium’s priesthood a tithe of men, materials and loyalty. The governor is also expected to reject enemies of the Imperium, and to ensure that the psykers upon his planet do not fall into witchery or possession. In return, the governor can call upon the priesthood (or Adeptus Terra as they are properly known) in times of dire threat and request aid. The Adeptus Terra comprises a bewildering variety of departments, bureaus, sub-divisions and offices, each of which deal with a particular aspect of maintaining the continuity of the Imperium. Each order has an obligation to care for its given area of control.

This weight of responsibility grows as feudal obligation passes up through a mind-numbing array of ranks within each Adepta. From lowly scribes computing a hive world’s annual nutra-slurry yield to mighty Sector Commanders overseeing the assemblage of a Crusading fleet, vassalage and power passes ever upwards to the titular heads of the Imperium, the High Lords of Terra. These powerful individuals rule from ancient Terra in the Emperor’s name. Based on Terra itself, the Emperor of Mankind is a silent being of awesome power. His withered carcass is cradled within an arcane artefact of incredibly advanced design from the Dark Age of Technology. This Golden Throne, as it is known, sustains the Emperor’s life force whilst He guards humanity from the Daemonic beings that would destroy Mankind utterly. For hundreds of centuries He has fought this psychic battle and for hundreds of centuries mankind has offered Him their fealty, worship and devotion.

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 12 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 organisations.

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, sub-sector, sector and Segmentum. 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 neo-feudal 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 organisations zealously protect information that could be used for the benefit of the Imperium as a whole, such as the widespread hoarding of technological and scientific information that is the common practice of 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 that is the realm of the Emperor is so massive and sprawling that it includes a wide variety of diverse worlds, ranging from pastoral Agri-worlds to jungle planets inhabited by Neolithic savages to polluted ecumenopoleis, great hive cities that are home to billions of people that in some cases cover entire planets. For example, the world of Gudrun is similar to an idyllic 18th Century Georgian-era Great Britain, with stately manors controlling vast estates of rolling green hills studded with small agricultural villages, while Catachan is a hellish Death World covered in a deadly jungle that is populated by giant carnivorous plants and animals (see Planets of Warhammer 40,000).

Adeptus Terra
Most of the organisations or organs comprising the Imperium's government are divisions of the vast Adeptus Terra (also called the Priesthood of Earth), the great bureaucracy of the Imperial government. The priesthood which serves the Lord of humanity is often referred to as “the right hand of the Emperor”. It falls to the Adeptus Terra to interpret His will and minister to the Imperium. Many hundreds of thousands of souls labour across the galaxy to serve this vast organisation. There are numerous ancient institutions that make up the priesthood, each with various names on various planets. These varying Adepta, as they are traditionally known, each have a specific function to carry out in the Emperor’s name.

There are countless divisions within the Adeptus Terra, and some are so secretive that their existence is known only to a few officials at the very top of the massive Imperial hierarchy. Perhaps the most well-known of the "secret" organisations is the Inquisition, the Imperium's secret police, which was created at the start of the Horus Heresy by the Emperor's regent, Malcador the Sigillite, to seek out any hidden threat to the Imperium from without or within. The existence of the other secret Imperial organisations is known only to the higher Imperial echelons. For example, one of the most secretive of Imperial organs is the Officio Assassinorum, the arm of the Imperium tasked with carrying out assassinations deemed necessary to the Imperium's security and survival. Other organisations are secret enough that nothing other than the fact that they exist is known, such as the saboteurs of the Officio Sabatorum and the Templars Psykologis, who carry out psychological warfare operations.

The most important and well-known Imperial Adepta include:


 * The Adeptus Administratum, which is responsible for the day-to-day administrative and bureaucratic functions of the entire Imperium. The Administratum is the largest division of the Adeptus Terra, and contains among its teeming numbers of Adepts countless scribes and petty officials. It administrates the Imperium at every level, assessing tithes and taxes, conducting population censuses, recording and planning and even delineating which threats to the Imperium must be dealt with and by which of the Imperium's myriad military forces. The Administratum consists of innumerable subdivisions, offices and departments. Needless to say, its servants are legion. At the will of the Adeptus Terra, the Administratum collects the Imperial tithe, sends out colonists, mobilises the military, catalogues planets and much, much more. Truly stultifying levels of bureaucracy exist within the Administratum and some wayward souls believe that the Imperium survives despite, rather than because of, its efforts. The Administratum has become synonymous with the Adeptus Terra in many places and, incorrectly, the terms are often used interchangeably. The faceless servants of the Administratum can be found all over the Imperium, ensuring that all things are accomplished in the correct manner, even if that may take a thousand years.
 * The Departmento Munitorum, itself officially a department of the Adeptus Administratum, which is responsible for supplying the armaments, materiel and basic logistics for the Imperial Guard across the galaxy.
 * Adeptus Astra Telepathica is the Imperium's network of Astropaths, the Sanctioned Psykers who are responsible for telepathically transmitting faster-than-light messages through the Immaterium and maintaining Mankind's fragile network of interstellar communications across the galaxy. Blessed are the blind, for they have looked upon the glorious light of the Emperor directly and no true servant of the Golden Throne could ask for more. Through the agonising ritual of soul-binding, these psykers have been gifted with a small portion of the Emperor’s own incredible will. Thus protected from the worst evils of predation by Warp entities, these unseeing servants of Terra can fulfil their primary function, preserving communication between the far-flung worlds of the Imperium.
 * The Adeptus Astronomica is the Adepta 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. The Black Ships of the Adeptus Astra Telepathica bring thousands of psykers to the birthplace of Mankind every day and many of those so tithed find themselves contributing to the vast psychic choir of the Astronomican. This steady beacon burns bright in the Warp; it is the Emperor’s will manifest, shining from Terra, and guides Navigators across the Imperium. The process of lending their psychic power to focus the beam quickly leaves the choristers as lifeless husks, but they give themselves willingly, for without the Astronomican the Imperium would cease to exist.
 * The Navis Nobilite is the Imperial aristocracy that is comprised of noble familes of mutant Navigators who pilot all Imperial vessels, military or commercial, through the constantly shifting dangers of the Warp and were the first known humans to display psychic abilities during the Dark Age of Technology.
 * The Adeptus Mechanicus is the priesthood of technicians and scientists dedicated to the religion of the Cult Mechanicus who build and maintain all advanced Imperial technology, vehicles, starships, and weapons of war and whose headquarters is located on Mars. The Adeptus Mechanicus believes that all knowledge in the universe is a sacred emanation of the Machine God and that the Emperor of Mankind is His Omnissiah. Needless to say, the Tech-priests and Adepts of the Mechanicus are viewed as only slightly better than the average heretic to the Priests of the Ecclesiarchy. Outside of Mars, the Mechanicus controls all of the Imperium's Forge Worlds, the planets where the production of most of its advanced technological items is done. The domains of the Adepts of Mars exist semi-autonomously within the Imperium, an empire within an empire, a right given to them by the Emperor Himself when he signed the Treaty of Mars that created the modern Imperium in the late 30th Millennium. They are the guardians of technology, the magi of machinery. It is theirs alone to know how to coax forth the life of a sun in a plasma containment field, how best to apply the blessings of activation and maintenance to the massive Titan war machines, how to ensure that the engines of the Emperor’s starships run smooth and true. The Adepts of Mars worship the Emperor in the guise of the Machine God. To them, Mankind is in a fallen state from the height of its powers during the Dark Age of Technology, when the secrets of the universe were known to all. Knowledge then, lies in the past and the Adeptus Mechanicus will go to any lengths to uncover the great secrets of antiquity, scouring the universe for any scrap of information from their holy book—the Standard Template Construct system. They hold that, were the knowledge contained within the ancient STC database to be restored in full, it would reveal all of the powers of the hallowed past. The Tech-Priests venerate machines and regard them as superior to flesh. Many of them believe that the Machine God desires them to shed this weakness and so they often sport numerous bionic modifications. These mechanical enhancements add to their air of otherness and further help to set them apart from the rest of humanity. Through rune and hammer, the Tech-Adepts are the wards of the arcane and they guard their knowledge jealously. But for all their might, they are not beyond the watchful gaze of the Inquisition.
 * The Adeptus Custodes are the genetically-emgineered superhumans who serve as the guardians of the Emperor's physical form. They are essentially the Emperor's bodyguards and royal guardsmen within the Imperial Palace on Terra and they are considered the greatest warriors of the Imperium, more powerful than even the Astartes of the Space Marines. However, despite their skill in battle they very rarely ever venture beyond the confines of Terra. These are among the mightiest warriors in all the Imperium, the praetorians of the Emperor. They stand ever-vigilant outside the brazen doors which seal His holy chamber. They are entirely beyond reproach and they are among the few in the Imperium over whom the Inquisition has no power. They never leave the inner sanctums of the Imperial Palace and serve from birth to death within its hallowed halls. Yet they are among the few servants of Mankind who will ever look upon the Emperor directly, and for that they receive blessings beyond all measure.
 * Adeptus Arbites - The Adeptus Arbites are the guardians of the Lex Imperia -- Imperial Law. It is given to them to maintain order amongst the higher echelons of Imperial governance -- wherever a Planetary Governor seeks to abuse his rule, wherever populist unrest seeks to unseat the rightful dominion of the Imperium, wherever thoughts of personal gain at the Emperor’s expense cross the minds of the ruling classes, there you will find the dogged agents of the Lawgivers. The Arbites enforces Imperial Law across the galaxy and its Arbitrators possess the right to serve as judge, jury and executioners on every Imperial world.
 * Officio Assassinorum - The Officio Assassinorum is the most covert of all the known Imperial agencies, whose assassins are responsible for removing the key leaders of any enemy of the Imperium as determined by the High Lords of Terra - whether that enemy is a threat from without or within.
 * The Imperial Inquisition - The Imperium is assailed by countless enemies both from within and without. The attentions of unclean xenos, the invidious influences of the misguided followers of the Ruinous Powers, planetary unrest, mutation, rogue psykers, rebellious Imperial lords and more all work constantly to bring the Imperium down, which will lead to the ultimate extinction of Mankind. Yet somehow it survives and humanity endures. The Inquisition is one of the many reasons for the persistence of Man in an extremely hostile universe. Known as the “left hand of the Emperor”, the Inquisition operates across the Imperium and beyond to suppress and eliminate those forces that would destroy the holy dominion of Mankind over the galaxy. Inquisitors are empowered to go anywhere and do anything —- whatever they must to ensure the survival of the Imperium. Their Inquisitorial Rosetta opens all doors, and even the vaunted Planetary Governors must acquiesce to their demands without complaint or delay, lest they be themselves regarded as suspect. They will commit acts, no matter how vile, to maintain the unchanging integrity of the Imperium, and they will put whole planets to death in order to see that this is so. The members of the Inquisition vary enormously in physical appearance, methodology and mentality. Some operate alone and in secret, hidden from the eyes of the common man, while others operate openly and carry dozens of acolytes and agents in their cadre. What they do have in common is that they answer only to their Order, and each Order answers only to the Emperor. Their efforts can be checked by no Adepta and they are utterly, fanatically devoted to the defence of the Imperium. Even the most loyal and honest Imperial citizen is likely to break into a cold sweat on learning that the Inquisition is nearby -- and that suits its members perfectly. The Inquisition is itself 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 civilisations 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--including within the Ecclesiarchy itself. 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 and they are perhaps the most powerful organisation within the Imperium after the Chapters of the Adeptus Astartes.
 * The Adeptus Ministorum is the ecclesiastical hierarchy of the Imperial Cult that promulgates and maintains control of the Imperial Creed and the galaxy-spanning faith of the God-Emperor of Mankind. The Adeptus Ministorum is not formally part of the Adeptus Terra. Rather it is a sister organisation which works hand-in-glove with the Priesthood of Earth. The Adeptus Ministorum derives its power and authority from the common Imperial belief in the Emperor’s divinity. Also known as the Ecclesiarchy, after its high priest, the Ecclesiarch, the Adeptus Ministorum is vast and powerful. Its duty is to guide and interpret the innumerable ways that humanity has found to worship the Emperor, shepherding the myriad worlds of man along the unsteady path that lies between heresy and true devotion. Whole worlds lie within its administration and on many others it represents the most powerful Imperial institution. Like the Administratum, the Ecclesiarchy is a complex and byzantine organisation. A bewildering hierarchy of priests, confessors, cardinals, novices, clerics, bishops and missionaries all owe fealty to the Ecclesiarch in the Ecclesiarchical Palace on Terra. Just as varied are the various roles within the Ministorum, from wandering missionaries, to charismatic preachers and theosophical scholars. Two of the most famous institutions within the Adeptus Ministorum are the training orphanages of the Schola Progenium and the Battle-Sisters of the Orders Militant of the Adepta Sororitas.

Imperial Military Forces
Mankind has always excelled at the art of war, and the Emperor’s armies are spread across the galaxy. The threat or effects of war are never far away, no matter where you go in the Imperium. Mankind seeks to purge the stars of its enemies, and the bloody carnage it wreaks in doing so shows no sign of abating. The Imperium’s military is at once mighty, glorious and terrible.The military forces of the Imperium include: lifetime of war are frequently gifted a portion of the very land they fought to conquer as a reward. As with many things in the Imperium, this is a mixed blessing indeed. The Imperial Guard Regiments are raised from the local armies of the Imperium’s worlds as part of a planet’s tithe to the Imperium. These regiments are normally deployed according to the orders of the Adeptus Terra. However, when the High Lords of Terra declare a major military campaign (often referred to as a “Crusade”) they appoint a Warmaster chosen from among high-ranking Imperial Guard officers to command the campaign’s regiments. One of the most famous Warmasters, Macharius, was given the title Lord Solar when he became the Imperial Commander of the entire Segmentum Solar. Macharius proved to be the greatest Imperial general since the Horus Heresy when conquered a thousand worlds on the Imperium’s Eastern Fringe and expanded the Imperium to the very edge of the Astronomican’s reach.
 * Imperial Guard - The Imperial Guard is the backbone of the Imperium’s military might. Millions upon millions of well-trained men and women, organised into thousands of regiments, make up the Guard. With Lasgun and bayonet they march upon alien battlefields and garrison vital worlds. They form the Imperium’s first line of defence and they strike the first blow in many Crusades. Its Regiments are drawn in great tithes of manpower from the Imperium’s worlds and each Regiment has a unique character and fighting tradition, from the rigid discipline of the Armageddon Steel Legion to the stealthy brutality of the pale-skinned Stygians and the unflinching bravery of the Vostroyans. Vast conscript armies, elite special forces, massive tank columns and glorious sabre-wielding cavalry can all be found in the Imperial Guard, often fighting alongside one another on Emperor-forsaken worlds they have never heard of. Regiments do not remain on their homeworlds but are raised explicitly to be sent to fight and die light years away from home. And die they do, for the Imperial Guard bear the weight of the Imperium’s wars. It is said that the Emperor knows the name of every soldier that has fallen fighting in His wars—but if that is true, He is the only one who can comprehend just how many Imperial Guardsmen have died in the ten thousand years since the Emperor "ascended" to the Golden Throne. Those who survive the grinding horrors of a
 * Adeptus Astartes (the Space Marines, including the Grey Knights and the Deathwatch, who serve as the Chambers Militant of the Inquisition's Ordo Malleus and Ordo Xenos, respectively)
 * Collegia Titanica (Division of the Adeptus Mechanicus that governs the Titans, the massive Imperial combat walkers)
 * Sisters of Battle (Orders Militant of the Adepta Sororitas) (Military forces of the Ecclesiarchy; select Orders of the Sisters of Battle serve as the Chamber Militant of the Ordo Hereticus)
 * Imperial Navy
 * Skitarii, the Legio Cybernetica and squads of Combat Servitors (Military forces of the Adeptus Mechanicus)
 * Inquisitorial Storm Troopers (the elite Special Operations troops that guard the secret installations of the Inquisition across the galaxy)

The Imperial Domain
The territory of the Imperium is defined by the reach of the psychic beacon of the Astronomican, which has a range of approximately 50,000 light years. The Imperium proper could thus be thought of as a sphere whose center lies at Terra's Sol System, and whose radius is about 50,000 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 centralised government would be unfeasible.

The Imperium encompasses countless worlds. No one has ever been able to map them and no one can even say how many there are. Entire departments of the Adeptus Administratum are devoted to cataloguing the worlds in the Emperor’s domains, a never-ending task, for it is in a state of eternal flux. Furthermore, the Adeptus Terra holds that the whole human race and the entire galaxy are under the Emperor’s rule—the Imperium has a manifest destiny to unite Mankind, impose its laws on every human world and destroy all alien life. The true scope of the Imperium is, therefore, the entire galaxy, though this is far from actuality. The Imperium jealously guards its territory whenever it can but its sheer size means that it cannot react to every circumstance. Many planets live and die alone, with only the truly great threats commanding the attention of the Adeptus Terra. Worlds are frequently lost to aliens, rebellion or disasters, with news of their destruction sometimes taking centuries to reach Terra. The Imperium’s borders undergo constant change, with new worlds discovered, conquered or colonised and old ones lost to xenos attack, Exterminatus or even to the Warp.

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


 * Segmentum Solar, the galactic "center," with the Sol System at its heart.
 * 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 Governor (or Segmentum Commander, the term used when the governor is acting in his military capacity) oversees his Sector Governors (or Sector Commanders), who in turn oversee Sub-sector Governors (or Sub-sector Commanders), who in their turn oversee the individual Planetary Governors, who are also known as Imperial Commanders. The higher ranks in this administrative system are usually combined with a basic planetary governorship as well as interstellar duties. Each of these governors is usually a member of the Imperial nobility and it is rare, but not impossible, for a man or woman born in the lowest ranks of Imperial society to rise to the rank of an Imperial Governor on his or her own merits or abilities. This neo-feudal 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 Feudal 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 (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.

Just as the environments and cultures of Imperial worlds vary immensely, so too does the way they are governed. The Imperium allows most of its worlds to govern themselves, using whatever method of government the population gravitates towards or was the traditional form of rule. Some are hereditary monarchies, others are ruled by aristocracies or warlords. Some are ruled by elected parliaments, while on others power is given to whoever can pay for it. On some worlds these are the same thing. Upon other planets, such things as democracy, free choice and even individual civil rights are present, though these worlds are few and far between. Some worlds are administered directly by the various Adepta, such as Agri-worlds run by the Administratum or Cardinal Worlds ruled by the Ecclesiarchy. Whilst the individual countries, states, tribes, corporations, hegemonies, peoples’ work collectives, and so on, may have their own various leaders, the Adeptus Terra will look to one person to fulfil the planet’s Imperial tithes and obligations to the Imperium. Titles for this governor vary from planet to planet. In some cases the person judged responsible for the Imperial tithe may not even be aware that this is the case until too late. Certainly, more than one titular head of state has discovered this upon rejoining the Imperium after a period of isolation through Warp Storm, war or other calamity.

All Imperial Governors are expected to recognise the authority of the Imperium and the Emperor and to uphold His laws. These responsibilities include aiding the agents of the Adeptus Arbites and the Inquisition, as well as arranging the allotted tithes for the Administratum. Governors are also expected to yield psykers up to the Black Ships of the Inquisition when required and to keep the population free of mutants, Chaos Cultists, heretics, political radicals and witches. In practice, some planets escape from these duties with relative ease, whilst others are placed under seemingly tyrannical restrictions. Due to the sheer size of the Imperium and the unpredictability of travel through the Warp, there are many occasions where the Administratum never manages to extract its levy, or the Black Ships never arrive at the appointed time to take psychic individuals away. Planets can be isolated for generations and it is not unusual to encounter worlds where the Imperial tithe has been all but forgotten. Certainly the scribes of the Prol System have, in their vast libraries, several accounts of Administratum Logisters arriving at worlds lost for centuries, only to discover their yearly tithe burning on vast pyres as the natives offer their dues up to the sky.

In some cases, a group of planets might have enough contact with one another to form political alliances and even minor interstellar empires. Other clusters of worlds might be connected by huge corporations, the powers of hereditary nobles, religious leaders or other such ties. In such cases, Planetary Governors must not only tend to the needs of the Imperium but also the whims of these power blocs.

Human Variability
The peoples of the Imperium vary in their form and appearances just as their homeworlds do. Whilst there is a generally agreed baseline human standard, consisting of four limbs, one head, twenty digits and so on, the local environment and genetic stock have caused all manner of interesting anomalies, evolutionary adaptations and fashions. These differences are usually cosmetic in effect; however, the more radical alterations walk the line between accepted variation and outright mutation. It is a subject of intense debate amongst some Inquisitors, and indeed the priests of the Ecclesiarchy, on what it is to be human and therefore accepted into the Imperium.

Certain planets will betray their colonial origins with the appearance of their peoples—perhaps a particular type of nose or skin colour will be dominant. Others will have clear tribal divisions. Some populations will possess unusual adaptations as a consequence of their local environment. The folk of the Agri-world Dreah, for example, have a grey skin, hair and eye tone, which exactly matches the flora, fauna, sky and waters of their notoriously dull planet. Some cultures may impose certain ideals of beauty that drastically alter the looks of their peoples. Certainly, many strange and terrible gangs of Underhivers have been discovered, clad in hyper-fashionable armour, sporting glowing electoos, skull studs, gang tribal mutilations and shiv scars with pride.

To some extent a similar appearance and culture binds the people of a planet together into a common stock. Usually speaking, citizens of the Imperium will prefer to spend their time with fellow natives of their world. That said, however, Mankind has ever been titillated by the exotic, so friendship, love affairs and even children with off-worlders is not unknown on planets with a culture that legitimises such travel.

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 the pursuit of outright war, there are many ways a rebellious world may be brought back into the Imperium. With the existence of its more secretive organs 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 as required.

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 in an ancient confederation that existed 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. Low Gothic (also called Imperial Gothic or simply Gothic) is the “official” language of the Imperium, the everyday tongue of its Adepts and of Terra. Most worlds have been a part of the Imperium for long enough to have adopted Low Gothic as a universal tongue but there are still a great many Feral Worlds on which Imperial Gothic is not spoken. Inevitably, dialects of Gothic differ from world to world and can be mutually unintelligible. Older planets frequently maintain archaic tongues of their own, to the extent that ruling aristocracies might only know enough Low Gothic to be sworn into their Imperial offices. For highly formal matters, the Adeptus Terra use High Gothic, the precursor language of Imperial Gothic. Many Ecclesiarchy rituals, Administratum edicts and Imperial charters use this ancient and venerable language.

Psykers in the Imperium
Humans with psychic powers, known colloquially as psykers, who possess abilities ranging from telepathy to pyrokenesis, have existed since the dawn of Mankind's existence as a species during the Paleolithic Age on Old Earth, but their position in the Imperium is an uncomfortable one at best. An untrained psyker is an unguarded gateway to the Warp, through which psychic predators like daemons and Enslavers can enter realspace and wreak havoc. It is said that whole worlds have been lost to hideous monsters of the Empyrean, while rogue psykers have committed horrible crimes with their powers or led dangerous and destructive cults. On some worlds all psykers are tried as "witches," subjected to tortuous ordeals and burned at the stake when their inevitable guilt is proven. Imperial law requires all worlds to monitor its psykers and subject them for testing by the Adeptus Astra Telepathica. Those who are strong enough to withstand the perils of the Warp are forced to endure the soul-binding and are trained to serve the Imperium as Sanctioned Psykers. Those who are too weak are taken away by the Black Ships and never seen again, their lives used to maintain the Emperor's strength within the Warp.

Travel in the Imperium
Interstellar travel between the worlds of the Imperium is rare and dangerous. The vast majority of civilians will never know the roaring tedium of shuttle flight, the sickening plummet of a Drop Pod or the unnerving silence of deep space. Given the huge size of the Imperium, it is impossible to cross it in the fleeting span of time given to ordinary men. Colonists, pilgrims and refugees spend many generations in the vastness of space, and many starships never survive the vagaries of travel to reach their destination.

Sub-Light Travel
Used mostly for journeys between planets or closely neighbouring star systems, sub-light travel involves speeds that confound mortal imagination and yet are still nothing when measured against the sheer size of the galaxy. Those attempting to use slower than light drives to travel any appreciable distance condemn themselves and their descendants to a shipboard life, endlessly whittling away the years until they arrive at the distant star they set out to reach. The average Imperial citizen is unlikely to experience slower than light space travel. Even those individuals living within a system with plentiful ships for interplanetary travel are likely to prefer the world of their birth over distant places with strange customs, odd food and “funny-looking” people. In many places, space travel is reserved for the privileged few who can afford to maintain the rituals, priests and shrines that such craft require, as well as the vast cost of the starships themselves. Tech-Priests do what they can to sate the Machine Spirits of these spacecraft, but often even their unfathomable lore is not enough to prevent these temperamental ships from venting their rage (and oxygen) to the detriment of passengers. Sheer odds dictate that sooner or later those that frequently travel in ships between planets will experience such a disaster. Those worlds that have not lost the art of creating and maintaining slower than light starships jealously guard their arcane craft. This reluctance to share their guild secrets ensures the reliability and price of their vessels but also robs others of vital information required to placate their own craft. Institutions such as the Imperial Navy, the Inquisition and various Adepta have access to much better-quality vessels, maintained with religious awe and reverence by countless generations of the Adeptus Mechanicus.

Warp Travel
To move any appreciable distance within the Imperium, voyagers must make use of Warp travel. This method of faster than light travel is rare, expensive and dangerous, as it requires the use of the unpredictable realm known as the Warp, or the Immaterium. Vessels equipped with a functional Warp-Drive are able to translate themselves into this other dimension of being by generating an envelope of protective Gellar Fields. These quixotic waves “bend” the starship through the veil of realspace into the Immaterium. Once within this strange hyperdimensional realm, the starship is able to ride the currents and eddies that flow within the Warp, frequently dropping back into realspace to check its positioning.

The Immaterium is a bizarre and contradictory place, entirely unnatural to Mankind or any being of realspace. Looking upon the Warp unprotected causes madness and Chaotic corruption, and thus is greatly feared by almost everyone in the Imperium. Dimensions, colours, forces and emotions operate entirely differently within the Warp’s embrace, and this can drive even the most thick-headed crewman insane. Psykers of course, find such travel even more disturbing as their mystical senses are able to comprehend much more of the Immaterium and the foul creatures that dwell within it. Those that travel through the Warp emerge to discover another of its disconcerting effects. Time does not operate normally within this other realm and so travellers can emerge to discover that centuries have passed in realspace since they started their journey, that they have merely been absent for a few seconds, or have even arrived before they left. Even skilled Navigators cannot predict how much time will be lost, gained or repeated over the course of a journey. Those that embark upon Warp travel know that they will probably never return home, or that if they do so they will find it so changed that it is unrecognisable. When two or more captains of starships meet, they invariably trade dates, attempting to reconstruct the time they are missing or have gained. Needless to say, Warp travel is not embarked upon lightly.

The Warp is occasionally prone to great turbulence or storms of activity. These strike at random and last for an unpredictable amount of time. Whilst these Warp Storms rage, any vessels within are tossed about on roiling currents, sometimes being spat out at random locations. Other ships simply become trapped, unable to translate back into realspace, cursed to an eternity upon the waves of the Warp. These storms disrupt communication across the Imperium and can sometimes herald a great disaster within realspace, as they did during the Age of Strife before the birth of the Chaos God Slaanesh during the Fall of the Eldar.

Imperial Communications
Just as travel within the Imperium is a complicated and inexact science, so too is the business of exchanging messages between the many and varied planets that make up the Imperium. Planetary communications systems such as vox-casters, hardwired telegraph and telephony lines and the more advanced vox-communicators suffice to pass messages amongst the nations of a world, yet have almost no use beyond the bounds of the planet’s surface. Such devices require many Terran years for their signal to reach even the nearest planet of a star system and have no surety of even being detected when they arrive. The perils of travel ensure that human or servitor messengers are just as unreliable and potentially as slow as radio or other energy wave communications.

The Imperium then, is forced to rely upon communication by psychic, or astropathic means. Astropaths communicate with symbols and iconic images, projecting these messages through vast distances of space by means of psychic power drawn from the Warp. This process is usually exhausting and requires ritual and focus in order to keep the psyker in the right frame of mind. These can take a wide variety of forms, such as use of the Emperor's Tarot, vision quests, automatic writing, trances, séances and the like. The Gaolist Astropaths of Hredin for example, spend many years etching their messages onto painstakingly illuminated sheets of iron and then destroy the work of art upon a massive grinding wheel when they are ready to transmit the information. The pain of annihilating a much-loved labour is said to produce psychic messages of unparalleled clarity.

These messages are received by fellow Astropaths in various ways. Some appear as vague and troubling dreams, whilst others appear as visions or mystic portents. Others appear within whatever ritual method or divination technique the receiving psyker happens to practise. Thus warning of an Ork invasion might appear as a glistening imperfection in fish entrails, a looming cloud of smoke, bleeding orifices or a worrying combination of runes or sigils within a holographic matrix. Astropathic messages must not only be transmitted from one Astropath to another but decoded at the other end. Each Astropath employs slightly different symbols and each has a preferred style or “flavour”. Some messages take weeks of poring over tomes of augurs and symbolism before they can be reconstructed, though the best Astropaths can do this word for word. Some remain a mystery forever. Some messages are received by Astropaths at entirely the wrong end of the galaxy and must be passed on to others who are nearer the place in question.

Some messages simply do not get to their intended recipient or are drastically misinterpreted along the way. In addition, there are too few Astropaths. Most worlds, especially those with small populations or on the fringes of the Imperium, have no Astropaths at all, and must rely on the infrequent visits of passing Chartist ships or Administratum census-takers to make contact with the outside galaxy at all. For this reason the Adeptus Terra cannot react quickly to every event in the Imperium, even when an event occurs that is great enough to attract the notice of the vast and ponderous bureaucracy. On most worlds, the Imperium feels very far away.

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.