The Imperial Government is nominally a monarchy with the Immortal God Emperor at its heart. However the Emperor has been silent for nearly ten thousand years now, interned upon His Great Golden Throne after receiving horrific injuries at the hands of Horus. After His interment, the Imperial government was reformed by His son, Guilliman, who placed the Senatorum Imperialis, most commonly called ‘The High Lords of Terra’, as the ruling body of the Imperium in the Emperor’s absence.
The High Lords rule with Imperial prerogative on their side and can demand the obedience of any servant of the Imperium, save only the Imperial Inquisition who owe their power directly to the Emperor personally through ancient authority granted to their secretive kind. However, because of the vast distances involved in governing the Imperium and the unreliability of interstellar travel and communications, the High Lords focus solely upon the issues that affect the Imperium as a whole, rather than the day to day minutiae of each of its worlds.
Each planet of the Imperium has its own system of governance. The great majority reflect the Imperium in that they are autocracies led by a figure commonly referred to as an Imperial Governor or Imperial Commander, though many hold local titles. More often than not this is a hereditary role, held by a member of the planet’s highest caste out of respect for tradition, and ‘right’ to rule rather than by merit. Though this is the most common form of Government (and the one the Imperium encourages when it installs the leadership of a newly conquered world), there are other systems, but they are universally authoritarian. Oligarchies and technocracies are the second most common; democracy is all but extinct, and where it does exist, there is only a single, Imperial, party. Totalitarianism is what holds the Imperium together, and it believes that freedoms like open democracies encourage idleness and disobedience.
Above local governments, each region of the galaxy is divided into administrative zones called ‘Sectors’. Each is ruled by a Sector Government or, if the Sector is under military rule as it is the subject of a large-scale military operation or ‘Crusade’, an individual granted the rank of Warmaster. The majority of Sector Governments represent the furthest reach of direct communication from the High Lords of Terra themselves; it is their responsibility to ensure that the worlds under their administration remain loyal and productive. They wield the might of the Imperial Battle Fleets and the Regiments of the Imperial Guard to keep worlds in line should they stray or fail to meet production quotas (or ‘tithes’).
Above the Sector Governments are the major administrative zones of the Imperium, the Segmenta: Segmentum Obscurus to the Galactic North, Segmentum Ultima to the Galactic East, Segmentum Tempestus to the Galactic South, Segmentum Pacificus to the Galactic West, and at the center of the Imperium, Segmentum Solar: the heavily defended cradle of mankind, and the location of Terra and the Sol System. The Prosperitas Sector is located in Segmentum Obscurus, bordering several Sectors vital for the defence of the Imperium from the periodic threats that emerge from the permanent Warp Storm known as the Eye of Terror.
The whole Imperium would collapse if it were not for the creaking inefficient Imperial Civil Service, the Adeptus Terra. This is made up of several divisions known as ‘Adepti’, each the equivalent of a a M.2 British Civil Service ‘Ministry’ with special responsibilities for a particular area of life in the Imperium. The majority of these relevant to most citizens are covered in other sections, but the single most prevalent of these, the Adeptus Administratum, plays an important role in the governance of the Imperium.
Without the Adeptus Administratum the Imperium would grind to a halt. Its legions of administrators, recorders, bureaucrats, scribes, political assistants, advisors and other dull-titled individuals are the grey-robed and dour-faced souls that ensure that the Imperium runs. Nominally all Governments are a part of the Administratum, but most like to show a semblance of autonomy and direct control. In truth, the Administratum runs almost all levels of life on a world, leaving policy and major decision making to the Imperium’s ruling caste while they go about the boring daily tasks, forms and paperwork upon which the Imperium is run.
Even so, the Administratum has a horrific reputation with most common citizens. Its obsession with imbuing in its employees an almost religiously fanatical obsession with guidelines, rules, procedure and a strict adherence to filling in the correct forms make them a nightmare to deal with if an average citizen wants anything done. A highborn citizen might well be able to speed things along a little with influence, but for the majority of citizens, while dealing with local administrators is not awful, anything that requires the approval of someone more senior can take days of forms and queuing before it is even heard; often it can be years before a request is confirmed by someone more senior, if it needs to be taken to the Sector level. Notoriously on frontier worlds is is not unheard of for birth certificates to be officially recorded for census on Terra as the death certificate for that citizen is leaving their homeworld.
For this reason and reputation, most citizens avoid involving the Administratum in their lives where possible.
Special Circumstances and the Prosperitas Sector
A handful of worlds enjoy a status outside the reach of the Administratum; these tend to be places of power for one of the other Adeptus Terra, such as the Adeptus Ministorum, the Priests of the Imperial Faith, who prefer their holy planets to be under their direct rule. Worlds at war or undergoing invasion often fall under the rule of a Military Officer but these situations are fleeting as that Military Governor is often quickly made an official ruler.
The Forgeworlds of the Adeptus Mechanicus are a unique entity. The Mechanicum or the Martian Empire is, in theory, a separate entity to the Imperium bound by ancient treaties over ten thousand years old. Though the lines are blurred by varying degrees of integration with the Imperium (some Forgeworlds have dual Imperial and Mechanicus governments) the Forge Worlds are mostly governed by the Mechanicus’ internal bureaucracy with any Administratum functionaries existing to ensure manufactured goods are routed to where in the galaxy they are needed.
The Prosperitas Sector is under the rule of a single Military Leader, known as a Warmaster. This is an ancient title of dark provenance bestowed upon a great leader in times of total war. The nature of the Prosperitas Sector is that it has been in a state of total war since its rediscovery, its military forces combined into a massive combined arms formation known as a Crusade. The Office of the Warmaster is designed to simultaneously provide leadership to the Crusade while directing the output of the Prosperitas Sector into supporting the myriad war efforts.