Imperium of Man

The Imperium of Man is the galactic empire under which the majority of humanity is united (Though there is some indication that their are other Humanoids in the Imperium). The founder and ruler of the Imperium is the god-like Emperor, the most powerful human psychic to date. Founding the Imperium ten thousand years ago, he continues, at least nominally, to lead it.

The Imperium is the largest and most powerful political entity in the galaxy, consisting of at least a million worlds, which are 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 can not be measured in terms of continuous territory, but only in the number of planetary systems in its control.

Several aliens and forces (the forces of Chaos, Tyranids, Eldar, Dark Eldar, Orks, Tau, Necrons) challenge the supremacy of the Imperium. From within, the Imperium is threatened more insidiously by rebellion, mutation, dangerous psykers and subversive cults.

Without the protection of the Imperium, mankind would fall prey to the countless perils that threaten it.

History of the Imperium
The Imperium was founded by the Emperor, also called "The Immortal Emperor", "God-Emperor", and the "Master of Mankind", at the end of the Age of Strife - a very long period of anarchy, war, and destructive regression which brought humanity to the brink of destruction and reversed the technological progression made in the Dark Age of Technology.

As the warp storms of the Age of Strife subsided, after having secured the scientific posts and spacedocks of Luna, along with the factories and scientists on Mars the Emperor began to unite mankind under his rule. A vast navy was built with which his armies undertook the Great Crusade, which lasted for around two centuries.

During this two hundred year long military campaign, the Emperor employed his most potent military units, the Space Marine Legions, lead by their born leaders, the Primarchs. These, combined with the might of the Imperial Army (which was later separated into the Imperial Guard and the Imperial Navy), brought thousands of human worlds together under the Imperium. The Great Crusade ended with the corruption and treachery of the Primarch Horus, the instigator of Horus Heresy rebellion.

The rebellion was fought across the galaxy. Horus, seeking to achieve a swift and decisive victory, lead most of the traitor forces directly to Terra. In the final decisive battle between the Emperor and the Arch-Traitor Horus, Horus was slain, leading to the break up of the rebellion. However the Master of Mankind was himself mortally wounded. His body was recovered by Rogal Dorn and according to his instructions he was placed on the life-preserving Golden Throne, where, for nearly ten thousand years, he has remained. Though physically a carcass incapable of movement or communication, his will, omnipotent, extends across the million worlds of the Imperium, beams the psychic energy of the Astronomican, soul-binds psychic humans and struggles against the daemons of the warp. He endures by his undying will, and by the sustenance that only the souls of sacrificial psykers can provide. By the numberless masses of humanity he is worshipped as a god and savior.

Political structure of the Imperium
The Imperium is still nominally ruled by the Emperor of Mankind. However, since his ascension to the Golden Throne, the duty of actually governing 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. However, the infeasibility of maintaining a completely centralized government over such a dispersed empire 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 as they see fit. Many Imperial worlds are left to fend for themselves without any direct involvement of the central government.

While most of the Imperium is a dystopia, the empire is so massive and sprawling that it includes countless different worlds, ranging from Neolithic jungles to polluted ecumenopoleis. 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 are divisions of the vast Adeptus Terra (the Priesthood of Earth). There are countless divisions, some are so secretive their existence is known only to a few. The most well known of the "secret" organizations is the Officio Assassinorum. Other organizations are secret enough that nothing besides their mere existence is known, such as the Officio Sabatorum and the Templars Psykologis.

The most important and well-known Imperial organizations include:


 * The Administratum, responsible for administrative functions, it 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 and departments.
 * Departmento Munitorium, a department of the Administration, responsible for administering and supplying the Imperial Guard.
 * Adeptus Astra Telepathica, the Imperium's network of astropaths, responsible for transmitting faster-than-light messages through the Imperium.
 * Adeptus Astronomica, responsible for maintaining the Astronomican which is used by the Navigators to navigate through the warp.
 * Navis Nobilite, Navigators who pilot Imperial vessels through the Warp.
 * Adeptus Mechanicus, technicians and scientists who build and maintain Imperial equipment, vessels, and weapons of war.
 * Adeptus Custodes, guardians of the Emperor's physical form.
 * Adeptus Arbites, galactic police force which enforces the Lex Imperia - the Imperial law.
 * Officio Assassinorum, the most subvert of all the known Imperial divisions, the assassins are responsible for removing key leaders of an enemy.
 * Inquisition, troubleshooters and internal affairs organization; they are responsible for investigating any potential threat to mankind or the Imperium. Its agents hunt down heretics, traitors, alien infiltrators and even daemons. They necessarily exist beyond the Adeptus Terra, as part of the Inquisition's role involves rooting out corruption and gross incompetence from the Imperium itself. They answer only to the Emperor and to themselves.
 * Adeptus Ministorum, the Imperial church which maintains the Imperial creed and faith.

The military forces of the Imperium include:
 * Imperial Guard
 * Adeptus Astartes (includes the Grey Knights and Deathwatch)
 * Collegia Titanica
 * Sisters of Battle
 * Imperial Navy

====

Imperial Domain
The disparate and widespread nature of Imperial territory means that a strongly centralized government would be infeasible.

The Imperium 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 heavily-fortified region due to the dangers posed by Segmentum's most infamous element, the Eye of Terror.
 * Segmentum Tempestus, the galactic south.
 * Ultima Segmentum, the largest province of all; its furthest extents are beyond the range of the Astronomican.

The Segmentae are the primary administrative division. Each is divided into sectors, which are areas of space. The sectors in turn consist of subsectors, each containing a number of star systems. These divisions and subdivisions are levels forming an administrative hierarchy.

Each Segmentum Commander oversees his Sector Commanders, who in turn oversees Subsector Commanders, who 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. Most governorships are hereditary, but it is also possible for a planet to have an elected Planetary Governor, a tyrant Governor who rules by force of arms, or anything in between. So long as the Governor fulfills his duties to the Imperium, his rule will generally be accepted by the higher authorities.

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 and psykers, as well as to collect the modest tithes these planets pay.

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 a adequate planetary defence force capable of defending the planet in the event of 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 or even years.

A relatively small number of Imperial worlds are not ruled by a Governor, but are overseen by an alternate organisation such as the Adeptus Terra, Ecclesiarchy, Imperial Guard or Space Marines. These 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 and worship of the Emperor (Ignatius Cardinal, Ophelia VII), and the Space Marine Chapter planets (Fenris, Macragge, Baal, Medusa).

Rebellion
The Imperial creed maintains that all of humanity must be brought and kept within the Imperium. Several Imperial organizations are permanently occupied with suppressing any possibility of rebellion before they have a chance of developing. The common worship of the Emperor holds mankind together and instills loyalty towards the Imperium. Rebellions and uprisings on Imperial planets nonetheless remain a constant. 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.

Besides outright war, there are many ways a rebellious world may be brought back into the Imperium. With its more secretive organizations, the Imperium is fully capable of carrying out subvert 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 dialects of Low Gothic over time. High Gothic (represented as Latinised English) dates from an age before the Imperium, and is used solely as a hieratic tongue by the divisions of the Adeptus Terra, the Inquisition and the Ecclesiarchy.

Imperial dating system
In Games Workshop published materials, the Imperium denotes years by the notation &lt;year of millennium&gt;.M&lt;millennium&gt;. For example, the year 40,999 would be 999.M41, while 41,002 would be 002.M42. However, 41,000 would be 000.M41, since the millennium starts on 001.M##.

Background to the Imperium in other Science Fiction
The Imperium itself, keeping with the dystopian themes of Warhammer 40,000 is a highly oppressive techno-theocracy very similar to 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.