Imperium of Orion Codex Entry

Imperium of Orion:
Governement:  Constitutional Monarchy
Capital:  Pax Imperius Station  (In rotating orbit of Coruscant, Earth, Terra, and T'au.)
Head of State:  The God Emperor of Mankind.
Founding Document:  The Anaxes Accord
Executive body:  The High Lords.
Legislative body:  The Imperial Senate.
Representative body:  House of Commons.
Judicial body:  Imperial Judicial Corps.
Population:  Exact number unknown estimates are around 20 Quadrillion.
Religious Affiliation:  Varies from world to world.
Currency:  Imperial Credit
Date of Founding: 2632
Brief History:
The first contact between any of the powers that would make up the Imperium of Orion occured in 2572.  While there was a some trade and exchange of information relations remained frosty as both sides had only recently come out of major conflicts.  Onto this scene emerged the Imperium of Man and its Eldar Allies in 2579.  
Relations remained tense and cautious.  Then in 2601 at a peace summit near the edges of all three powers an altercation occured with all sides claiming delegates from another faction attempted to assassinate them.  The Great Galactic War had begun.
The Orion Systems Alliance seemed to be the underdog coming into the conflict, considerably out gunned by its enemies.  It lacked the force wielding Jedi of the Republic or the Super Soldiers of the Adeptus Astartes but sheer determination, cunning, and superior technologies in the areas of Artifical intelligence, Mobile Suits, and biological augmentation gave them enough of an edge to keep both factions at bay.
The brutal three way became a horrific four way as the Tau entered onto the stage attacking all factions involved.    The battles raged on a hundred worlds for a decade, with atrocities committed by all sides such as the Orbital Bombardment of Equestria or the Massacre of Ossus.  It was not until the coming of a greater threat that all four factions were forced to unite to face it.
The Tyranid Hive Fleet Behemoth arrived devastating countless worlds in its path.  Alone none of the factions could present effective resistance against the Tyranids.   In desperation they united their forces and fought the alien monsters as a united front.
All of this came to a climax at the battle of Macragge in 2616.   There millions of soldiers from all factions sacraficed their lives to shatter the Hive Fleet.  Though weakened the Splinter Fleets remained a serious threat for the next twelve years.
To guard against a similar conflict in the future all of the major factions began to open talks towards forming a united government in 2629.  It would take another three years of arguing, compromise, and near reignition of hostilites before the new Government took shape.  In 2632 the Imperium of Orion was founded.
Ever since that day the Imperium has stood strong in face of rebellion, alien assaults, and worse threats.  Its might however was tested most gravely in 2653, when the Sith Empire returned to the Galactic stage and invaded the Imperium.  Expecting to face a weak Republic and exhausted Jedi they were surprised and alarmed to find the might of the Imperium waiting for them.  A bloody war broke out lasting for nearly two decades before exhausted, both factions negotiated a peace treaty, one that was marred by the Sith making one last cowardly attack to try and break the Imperium.   The treaty of Coruscant established the new boundaries between the two powers and allowed the Imperium to refocuss its efforts against Tyranids and other threats.
The Reaper war or Third Great Galactic War proved to be the Imperium's finest hour.  Entering late in the war the Imperium's mighty forces turned the tide of battle against the Reapers.  From Cadia to Palaven they fought until at last the Reapers were thrown down in defeat and Citadel Space was annexed into the Imperium to speed the healing of a wounded galaxy.
Without a doubt the Imperium of Orion is the most powerful nation in the entire galaxy, but even its strength is near its limits.

Organizations:
Council of the High Lords-
The Council of the High Lords is a body of executive leaders how directly advise the Emperor.  It is made up of the Master of the Administratium, the Farbicator-General, the Supreme Chancellor, the President of the House, the Eldest Sister,  a representative of the Jedi order, a representative of the Inquisition, a representative of the Eldar Craftworlds, the Grand Master of Assassins, the Warmaster Horus, the Captain General of Adeptus Custodes, the Grand Provost Marshal, the Master of the Adeptus Astra Telepathica, the Master of the Astronomican, the Parternoval Envoy, and four others who are chosen from various other branches of the Imperial Government and Military.    While they are officially the Emperor's advisers they each act with considerable authority and their words carry much weight.

The Senate-
A hold over of the Old Republic the Senate is one of the two legislative bodies of the Imperium.   Planets of sufficient importance are granted a Senatorial seat.  The Senators are often chosen by the Planetary Government though in some cases they are voted on by the populace.   There are thousands of Senators who all meet on Coruscant.  The Senators will elect the Supreme Chancellor, who represents the Senate on the Council of the High Lords.

The House of Representatives-
The House of Representatives is one of the two legislative bodies of the Imperium.   Sometimes called the voice of the people the house is known for being fractious, temperamental, and generally a pain in every other part of the Imperial Governments neck.  The House is elected  by the people of individual Star systems.  The Number of seats any star system may holds is based on population measured in billions.   However each inhabited star system is allowed a minimum of one seat.  As such the House has roughly 20 million members.  Seeing as how that is the population of a small country the House rarely is all gathered at once.  The rare occasion when the whole house is present is usually on matters of dire consequence or the most extreme of crisis situation.  The House meets on Earth and is officially lead by the President of the House who holds a seat on the Council of the High Lords.

Jedi Order-
The Jedi Order, sometimes referred to as the Holy Order of the Jedi Knights, is an ancient monastic peacekeeping organization unified by its belief and observance of the Force, specifically the light side. The Jedi are the guardians of peace and justice in the Imperium, and become among most famous of the various groups that rely on the Force for their power. Led by a series of Jedi Councils, the Order has grown over the millennia despite facing many trials, most often threats from the Sith, wielders of the dark side of the Force.   Currently based on Tython.

The Imperial Inquisition-
The Inquisition is the hard left hand of the Imperium.  Inquisitors seek out corruption and hersey with the Imperium, from politicial disidents to renegade psykers and force users.  Inquisitors posses nearly limitless power and may demand the service of any Imperial Citizen from the lowest commoner to a Planetary Govenor.  They can not however demand the usage of Space Marines, Jedi, or Magical Girls and instead must ask for their assistance.

Grey Knights-  The Grey Knights are a specially trained force of Space Marines created from the Emperors own Geneseed.   Untold numbers of rites are preformed upon them for one reason and one reason only, to battle Daemons and heretics.   The Grey Knights are considered top secret so much so that in some cases planetary populations may be slaughtered to prevent information about them from spreading.

Death Watch-  The Death Watch are normal Space Marines on lone from various chapters to hunt and kill Xeno's.   Death Watch Marines who return to their chapters often bring with them new tactics and technology as payment for their services.

Adepta Sororitas- (also known as "the Sisterhood" or "Daughters of the Goddesses") are an all-female subdivision of the religious organisation known as the Temple of Magi. The Sisterhood's Orders Militant serve as the Temple's fighting arm, mercilessly rooting out corruption and heresy within humanity and every organisation of the Adeptus Terra.   They are frequently used by the Ordo Hereticus.  

Magi-  The more informal fighting forces of the Temple of Magi the Magi are a mostly female group able to wield magical powers bestowed upon them by the Goddesses Madoka and Homura.  These powers not only allow them to preform superhuman feats but also make them an excellent counter to daemons and darksiders.  While mostly safe from the dangers of the warp some spells of the magi do blur the lines between Magic and Sorcery.  Magi typcially either operate on their own or in small groups of no more than five.  Some Magi may create a familair who can aid them in battle, spell casting, or even basic house hold tasks.

Adeptus Arbites-
The Adeptus Arbites enforce the Lex Imperialis, Imperial law, embodied within the great Book of Judgement. Their organisation represents the soldiers and police of the Adeptus Terra.   While many worlds have their own laws and the Arbites are the formal policing force of the Imperium.

Adeptus Mechanicus-
The Adeptus Mechanicus is a technological organisation, often known as the Priesthood of Mars. It holds a near monopoly on technological knowledge in the Imperium. Their Forge Worlds turn out the Imperium's most powerful and advanced weaponry and equipment.

Collegia Titanica-  The Collegia Titanica is the section of the Adeptus Mechanicus that includes the Imperial Titans, the colossal god-machines. The Collegia is also known as the "Adeptus Titanicus" (a contraction of "Adeptus Mechanicus Collegia Titanica").  

Officio Assassinorum-
The Officio Assassinorum (Office of Assassins) is the Imperial organization responsible for the recruitment, training, and deployment of elite assassins.   That said it has been open to corruption in the past, with some Grand Masters murdered by their own students.
Vindicare Temple - sharpshooters, specialists in sniping and marksmanship.
Callidus Temple - chameleons, specialists in infiltration and impersonation.
Eversor Temple - berserkers, drug-fuelled killing machines.
Culexus Temple - Pariahs, psykers are their exclusive targets.
Venenum Temple - specialists in poisoning their targets.
Vanus Temple - intelligence-gatherers, in matters of strategy and tactics their insight is unparalleled. They often assassinate their targets indirectly using their intelligence and knowledge to bring down targets.

Adeptus Astra Telepathica-
The Adeptus Astra Telepathica is an organization of the Adeptus Terra, responsible for the recruitment and training of psykers into the service of the Imperium. The Adeptus Astra Telepathica trains the majority of Imperial psykers, which become known as Sanctioned Psykers.

Military Forces:
Imperial Army-
The Imperial Army is a broad base term used to describe the majority of ground forces utilized by the Imperium.  It is a diverse and complex force with a vast array of weapons and vehicles.  It can be broken down to further levels.

Planetary Defense Force- Called PDF for short a Planetary Defense Force is the standing militia on all Imperial worlds.  Every planet in the Imperium is required to maintain a PDF force.   As the PDF is focussed on defensive warfare and occassionally putting down a rebellion, most have little actual battlefield experince.  In times of war where a planet is attacked by hostile invaders and other branches of the Imperial army arrive the PDF usually become subservient to the more experinced forces.   It is from the PDF that most Guard Regiments are raised.

Imperial Guard- Often called the Hammer of the Emperor the Imperial Guard is the primary standing army of the Imperium.   Guard regiments are formed on various worlds creating a diverse fighting force, each regiment has its own culture, history, and traditions.  The Imperial Guard's greatest advantages have always been its superior numbers, powerful armored units, and universally issued massive adamantine balls.  It is actually impossible to properly guage just how many guardsmen are in service at any one time due to high casualties and a roughly equally high recruitment rate.  On average a new regiment is raised twice in a month, which of course does not count new recruits replacing slain members of a regiment.   Most guardsmen rarely get to see home though most regiments try to make a habit of returning to their homeworld at least once every five years.

Clone Army-  With constant tyranid, sith, and ork attacks the Imperium's forces began to become very thinnly stretched.  Jedi Master Sifo-Dyas, ordered the creation of a Clone army on the Planet Kamino.   First taking to the battlefield at Geonosis the Clone Army is primarily focused on fighting the CIS.  They are typically lead into battle by the Jedi as the war with CIS is considered an internal dispute.  There are currently around two billion Clone soldiers in service.

Imperial ODSTs-  The ODSTs or Orbital Drop Shock Troopers, are elite soldiers who deploy ahead of invasion forces in drop pods.  They disrupt enemy forces on the ground, eliminate enemy strong points, and secure vital positions ahead of the main army.  The ODSTs are fiercely loyal to their organization and maintain rivalries with other special forces units.  Typically rolled up as Stormtroopers.

Biotic Corps-  Biotics are strongly encouraged to join the Imperial guard and often serve in seperate units attached to guard Regiments.   Biotics supress or weak magical, warp, psionic, and force based powers as was intended by the Reapers.  Their powers however can be flexible enough to be applied to a wide variety of situations.

Mobile Suit Squadrons-  Mobile Suits are large mechanical warmachines roughly the size of a scout titan.   First developed during the one year war Mobile Suits are faster and more maneuverable than titans but often lack comparable armor or weaponry.  They often deployed in sorties of between two and six units.  Mobile Suits are used by both ground forces and naval forces.

Commissariat-  The Commissariat is a department of the Departmento Munitorum overseeing the activities of the Commissar officer corps within the Imperial Guard. The Commissariat attaches Commissars to most Regiments of the Imperial Guard to inspire its men, boost morale, and if necessary take control when its commanders or men are demonstrating a lack of zeal or competency. The Commissariat also recruits potential Commissars from the Schola Progenium then trains them for their duties within the Guard.

Imperial Navy-
Like the Imperial Army the Imperial Navy covers a wide array of space borne forces.    It is of note however that the Jedi and Adeptus Astartes maintain their own and often very different space forces.

Merchant Flottila-  While not technically part of the standard military all ship owners are required to sign a letter of mark stating that in any crisis or war time scenario their vessel willl be made available to military forces and disaster relief teams.

Orbital Guard-  The space borne cousin of the PDF the Orbital Guard are local gunboats and patrol ships that maintain anti piracy duty.  In times of war they will be levied into the fleet to protect their world.  While most of such ships are small, some wealthier worlds can produce or purchase larger vessels.

Imperial Fleet-  The main fighting force of the Imperium of Orion's navy.  Ships of almost a hundred different classes, makes, models, and tonnages make up the hundreds of thousands of ships in the Imperial fleet.  The Fleet possess the power to devastate whole worlds with a mere after thought, or obliterate entire sectors.  The exact number of war ships is estimated to be between 50,000 vessels and 65,000 vessels.

Adeptus Astartes-
The elite super soldiers of the Imperium the Imperial Space Marines are possibly the greatest warriors in the Galaxy.  Originally there were twenty legions of Space Marines numbering around ten thousand marines.  Each Legion was lead by a Primarch, a genetic clone of the Emperor (essentially a super test tube baby).   The Primarchs are as follows:
Lion El'Jonson
Rachnus Rageous
Fulgrim
Perturabo
Jaghatai Khan
Leman Russ
Rogal Dorn
Konrad Curze
Sanguinius
Ferrus Manus
Hecate Moor(The only sister in this brotherhood)
Angron
Roboute Guilliman
Mortarion
Magnus the Red
Horus (The Warmaster and the Emperor's favored son)
Lorgar Aurelian
Vulkan Nocturne
Corax
Alpharius Omegon (A pair of twins who shared control of the Legion and remained a secret until the Codex debate)
During the negotiations for the formation of the Imperium of Orion at the end of the great Galactic war the matter of the Imperium's Space Marines was brought to the table.   While the Space Marines had been invaluable in stopping the Tyranids many feared then dangers presented by such indominatable warriors.  Most of the delegates refused to sign anything until something was done to curtail the power of the Space Marines.

Roboute Guilliman, composed the Codex Astartes which would reform the Space Marine legions into chapters.   These smaller chapters would be limited to 1,000 marines each and be independent of their forebearers.   Guilliman's proposal however was meet with a furious debate amongst the Primarch's that nearly resulted in civil war.  Eventually deals were cut and agreements made and the Codex was adopted.   The twenty Space Marine Legions were broken up into around a hundred chapters.
Imperial Special Warfare Forces-
Spartan Corps-  The Spartan Corps are elite super soldiers, while not as powerful as the Astartes they are far easier to produce.   The Spartan corps are deployed to high risk missions where Space Marines would either be impractical or are unavailalbe.

Imperial Commandos- Commandos are special forces soldiers deployed for high risk missions within warzones.  They take out strategic targets, secure valuable positions, force recon, anything that simply can't be done by regular infantry with out serious casaulties.  They are often employed as body guards by important Inquisitors and Officers.