40px-Terminal.png This article, Interplanetary Commonwealth, was written by Specops306 and The All-knowing Sith'ari. Please do not edit this fiction without the writers' permission.
Help This article, Interplanetary Commonwealth, is currently under active construction.
UNSC WARNING: This document, Interplanetary Commonwealth, is property of the UNSC and is Classified [NOVEMBER BLACK], protected under Office of Naval Intelligence Security Protocol 1A. Disclosure of its contents to, or access or alteration by, personnel with a clearance level lower than GAMMA THREE is an offense punishable by court(s) martial and imprisonment or execution for treasonous acts. Failure to disclose confirmed or suspected breaches of security will be treated as complicity, and is punishable by dishonourable discharge and/or imprisonment.
Lieutenant Commander Michael Pomare, Office of Naval Intelligence, UNSCDF Navy
ONI Seal 1
Interplanetary Commonwealth
Political information
Type of government

Parliamentary confederation


Charter of the United Nations

Head of State

Secretary-General of the Interplanetary Commonwealth

Head of Government

Secretary-General of the Interplanetary Commonwealth


Supreme Commander of the UNSCDF

Executive branch

Interplanetary Commonwealth Cabinet

Legislative branch

Interplanetary Commonwealth Parliament

Judicial branch

Supreme Court of the Interplanetary Commonwealth

Societal information


Official language




State religious body

None, secular

National holiday

Foundation Day


To the Stars, in Peace

Historical information
Formed from

22nd Century


The Interplanetary Commonwealth (also referred to as the I.C. or the Commonwealth) is a federal, constitutional confederation comprising 806 colony worlds in 781 star systems. The country is situated mostly in the Orion Arm, but maintains military installations abroad in the Perseus and Sagittarius arms.

With a population of over 40 billion people, the I.C. is the third or fourth largest country by area covered in light years, and the third largest in terms of population. The Commonwealth was formed in the 22nd century in the aftermath of the Interplanetary War, which brought a great deal of suffering to both the colonial population and the residents of Earth, but also united humanity's military forces into a common armed force under the United Nations Space Command (UNSC), which serves as the military, exploratory, and scientific force of the I.C. The Commonwealth united the various states of Earth and off-world colonies in a democratic confederation.

Prior to the Covenant attack on Harvest in 2525, humanity was in chaos. Battles on multiple fronts and planets evolved from a group known as the Insurrectionists who wanted independence from the Commonwealth. The UNSC, more specifically, the United Nations Space Command Defence Force, constantly battled against the Insurrectionists. The I.C. faced near-annihilation with the outbreak of the First Great War. This fact allowed the UNSC to override civilian rule and establish itself as humanity's primary government. Although the Unified Earth Government was more open to step down, the Colonial Administration, the arm of the UEG ruling over the colonies, resisted the UNSC's rise to power, and was thus stripped of its power. By 2552, Earth was the last remaining major human bastion; and fell under attack by the Covenant forces. The war finally came to an end after a UNSC and Covenant Separatists force eliminated the Covenant leadership.

Successive wars such as the War of Vengeance and the Second Great War have confirmed the country's status as a military power. It emerged from GWI as the first country with NOVA weapons. The end of GWII has left the Interplanetary Commonwealth and the Unggoy Star Empire as the sole superpowers. The I.C. accounts for 40% of galactic military spending and is a leading economic, political, and cultural force in the galaxy.


Formation and expansion

It is a truism that strength is found in numbers. Independent nations have fought countless conflicts since the beginning of human civilisation: primitive tribesmen repelling rivals from their land; city-states fighting for political and economic superiority; vast empires hurling artillery at each other in the name of monarch and homeland. It is therefore unsurprising that, in the wake of slipspace technology and the development of the first great colony ships, the UNSC fully expected this pattern to repeat itself in the stars. For this purpose, the Interplanetary Commonwealth was formed - ostensibly to foster improved diplomatic and economic relations between the colonies, it would eventually be appropriated the Colonial Administration Authority to reign in movements towards independence or self-sufficiency. With the first colonies established in the early 24th century, and humanity rapidly moving outwards in an ever-expanding sphere as new colonial prospects were discovered, the need for a diplomatic network tying these colonies together became apparent - trade disputes between Alpha Centauri and Beta Centauri colonies over exclusive rights to import/export became a major standoff issue, while efforts by the CAA to work through its own channels simply broke down because the negotiators had little experience with the issue. Intervention by the Cygnus colony eventually saw the dispute resolved, though to neither party's satisfaction, but proved the idea of a "community of planets." Insurrectionists argue that there is no distinction between the Unified Earth Government and the Interplanetary Commonwealth, given the significant power the Earth delegates wield over the colonial Parliamentary assembly, but saying the two are synonymous would be a mistake. While Earth would take the fore in internal policy and government, the Interplanetary Commonwealth was not entirely toothless.

Civil War

It is equally true that unity's greatest threat is stress, and there has been no greater source of internal stress in recent human history than the Insurrection. An exact timeline is difficult to pinpoint, due to the nature of the parties involved. Colonial independence movements have existed since the Odyssey first ventured out beyond the confines of the solar system, but their increasingly militant nature can be traced back to the early 2490's. While the Commonwealth is meant to resolve its own issues through dialogue in the Interplanetary Commonwealth Parliament, the CAA has made a reputation from its interference, sometimes backfiring disastrously. Some took issue with rules restricting interplanetary commerce, believing them to protect the UNSC's virtual monopoly on space travel. Others resisted CAA efforts to introduce "conformity laws", intended to standardise colonial legislation and codify them into one set of colonial laws, ignoring the different conditions of many colonies, especially the frontier "outer" colonies. Still others took up extremist positions incompatible with the spirit of the United Nations Charter adopted by all members of the Interplanetary Commonwealth - during the subsequent conflict, the dizzying number of communists, socialists, fascists, theocracies, and other extremist regimes that propped themselves up throughout Commonwealth space would all reject the charters, denouncing them as relics of a bygone age and each claiming to usher in an age of peace and prosperity - and that this would be "extended to our colonial brothers, by the olive branch or by the sword."

Much has been made of how the Insurrection might have amounted to more than just a civil war, and may have seen humanity's self destruction. The UNSC would spend more than thirty years trying desperately to hold the colonies together, fighting against various factions of varying degrees of belligerence. On some worlds, simple negotiation was all it took - against all expectations, the dual Islamic and Jewish colonies of Cygnus were never much of a trouble spot despite the historical antagonism Muslims and Jews are supposed to have. At the other end of the spectrum, Far Isle rose up in 2492 and ejected the UNSC Army garrison, declaring it's independence - the subsequent order to bombard the planet with nuclear weapons in reprisal would result in General Henry Stanley being tried and convicted my courts martial of crimes against humanity, but would do nothing to stop the colonies seeing this as an act of desperation by a tyrannical regime. If the Insurrectionist groups could, perhaps, have pooled their resources and built alliances, the threat they posed would have been exponentially increased - with contacts in Cygnus, a group in Eridanus could learn in advance of a UNSC fleet approaching. Fortunately, the sheer degree to which these groups differed often proved a hindrance - the People's Republic of Minorca made overtures to the United Rebel Front, which was rejected by the libertarian group as being a virtual autocracy under "General" Isandro Gilberto Anacleto. Even despite shared religious beliefs, Islamic extremists from Coral were rejected by the more peaceful New Jerusalem colony for their demands of a permanent Islamic homeworld through militant means. If the Insurrection had unified, Earth would have been isolated and alone amid a sea of humanity - instead, it would fracture apart on its own, with groups often turning upon each other as they struggled for control. Star systems with more than one independence movement, such as Epsilon Eridani, would see hundreds caught in the crossfire as rebel groups attacked each other, further complicated by loyalist militias formed to protect isolated communities, with UNSC Marines, Sailors, Airmen and Soldiers barely able to distinguish friendly and hostile factions.

With the Commonwealth being literally torn apart, with more and more colonies withdrawing from Parliament each year, it may very well be that the Commonwealth would eventually have collapsed as the conflict spread. It was a disaster on unparalleled proportions, threatening the shattering of the human race, and perhaps near extinction. But it did have some unexpected benefits - in dealing with these threats, the UNSC was forced to return to a military role, abandoning the peacekeeping nature of its recent past, once again adopting weapons and tactics that had once been set aside in the name of peace. Naval advances would see improvements in slipspace navigation, though marginal, and the development of new weapons and defences, the most famous of which would be the Magnetic Accelerator Cannon, the most successful coilgun series ever deployed by humanity. Tactics and strategies were developed for asymmetric warfare, and the UNSC would come to understand the nature of a defensive guerilla war with an intimacy that would serve it well when the tables were turned.


Great War

As devastating as the Insurrection was, it would be the onset of the Human-Covenant War, retroactively known as the Great War, that would nearly destroy the Commonwealth. While Harvest is well known on record as the first human colony destroyed by the Covenant, partially glassed in 2525, it's small size and remoteness from other colonies destined it for immediate obscurity. In the immediate future, it would be the unprovoked and unexpected hammer blow against Bliss in 2526, a much larger world, that opened humanity's eyes to the menace posed by the Covenant. Over the next ten years, hundreds of Outer Colonies would fall to the Covenant as their ships flooded into human-occupied star systems. Attempts to slow the advance would have some success - special warfare operations against vital targets, such as shipyards and refineries, would set the Covenant war machine back by months, while the implementation of the Cole Protocol would finally plug the crippling security leaks that had led to so many colony worlds being destroyed with such little effort. The war would also have the unexpected benefit of finally ending the Insurrection - extremist hard-liners, such as the United Rebel Front, would remain until and beyond the end of the war, but robbed of the influence they once wielded. Against the Covenant humanity would finally reunite to face a common foe.

Nevertheless, the loss of hundreds of worlds was a crippling blow to the Commonwealth. The Outer Colonies had been major producers of raw materials, shipping valuable metals and minerals, foodstuffs and various goods to the larger, consumer-based Inner Colonies. It would take the combined efforts of most of the Commonwealth's member colonies to economically stabilise, distributing the necessary infrastructure between themselves - the loss of Harvest, and subsequent waves of famine on worlds that had once depended on it for produce, proved the concept of "basket worlds" non-viable, lest a single Covenant strike cripple dozens of worlds. Henceforth, colonies would create "victory gardens", using public land to grow emergency crops. Restrictions on genetic modification were removed, creating super-crops that grew faster and produced more, despite health concerns raised by some. The old frontier industries were restarted, such the titanium mines on Reach. Private mining corporations would examine the old art of asteroid mining, capturing promising prospects within a star system's asteroid belt, accelerating them further in-system via large mass driver, catching these metal-rich chunks of rock and stripping them of usable materials. The transition from a consumer to a producer-based economy was not easy, and it was not quick, but it was made and by the late 2530's the situation had stabilised significantly. Inner Colonies would be lost throughout the next decade, but at nowhere near the rate at which the Outer Colonies fell - with the Cole Protocol implemented by the UNSC, the Covenant found a major stumbling block to their goals. The increasing effectiveness of UNSCDF personnel and equipment, as recruitment drives among colonists, refugees and Earth-born populations bolstered their numbers, and modernisation drives vastly improved the effectiveness of the human arsenal, further slowed the advance of the Covenant to a colony every few years, rather than the hundreds lost in the first ten years of the war.

With the devastation of Earth in 2552, and the conclusion of the Great War, the Commonwealth would take up much of the slack as humanity rebuilt. Protected by UNSC Naval convoys, refugees would flood into Earth to restore the planet to self-sufficiency. Billions had been killed by the Covenant's invasion of the planet, especially in Africa, Oceania and North America, but colonial refugees would repopulate these areas. Infrastructure restoration projects, rebuilding the cities that had been destroyed, would provide work for the sudden population influx, and would be the force behind an economic post-war boom period, further bolstered as resources and support poured in from the colonies. Earth, once a hated symbol of oppression, had finally become what the UNSC had insisted it had always was - a symbol that transcended borders and light-years, the cradle of humanity, the very core of the human race. The UNSC would begin its own restoration projects - the transplantation of naval bases and shipyards to Alpha Centauri, re-terraforming projects using Sangheili-provided equipment to speed the process, planetary surveys to find planets where the surplus refugee populations could be resettled - but the Commonwealth would do most of the rebuilding.

War of Vengeance

Main article: War of Vengeance

The outbreak of the War of Vengeance did little to set back the reconstruction process for the Commonwealth. The Blood Covenant would prove a formidable enemy, but during the next seven years the Brute-dominated Covenant offshoot would only target two civilian targets, neither of which had been designated as significant repopulation prospects - the shipyards and space docks at Sigma Octantus IV, Cote d'Azure, and the asteroid mining industry of 23 Librae.

Cold War

Government and politics

Foreign relations and military