The Halo universe is a fictional setting for the video games Halo: Combat Evolved, Halo 2, and Halo 3, the future game, Halo Wars, and the books (including the graphic novel), spin off media I Love Bees and Iris related to the Halo series.

Concept and creation[]


United Nations Space Command[]

Main article: United Nations Space Command

The UNSC is the main military defense branch of the Halo universe's unified human government (which evolved from the modern day United Nations). It has been reduced to a handful of Inner Colonies, with Earth being the political center. As revealed by the events of Halo 3, Earth is currently occupied by Covenant forces.

UNSC Planets and Locations[]

  • Earth - The human home planet, heavily fortified with 300 Super MAC Platforms and having the second of the two United Nations Space Command Headquarters. Africa seems to have become a developed region, as indicated by the City of New Mombasa, but no other locations or their conditions are given. Earth is being invaded with Africa being occupied by Covenant forces during Halo 2 and Halo 3.
    • New Mombasa, East African Protectorate - The first city attacked when the Covenant invaded Earth in October 2552. The Ark, a Forerunner structure that commands the Halos, is rumored to be located just outside of New Mombasa, somewhere between the city and Mount Kilimanjaro. In the final story in the Halo Graphic Novel, "Second Sunrise over New Mombasa", a journalist and several Marines overhear a conversation between two Elites, one of whom confirms that the Ark (see below) is present at New Mombasa's location and that they must clear the area to secure it. Much of the city was apparently destroyed when the last Covenant carrier left from the initial assault group made an in-atmosphere Slipspace jump to escape the human forces; several buildings were seen to follow the carrier out of the jump when it arrived at Delta Halo. However, it is revealed later in Halo 3 that the device buried under New Mombasa is merely a massive slipspace portal device that leads to the Ark.
    • Song Nam - This is where the MJOLNIR Mrk. VI powered armor suit worn by the Spartan-117 was fabricated.
    • Sydney - This population centre features a military base (UNSC High Command) as in Halo: First Strike.
    • Voi - A port city that is home to a Traxus industrial facility and is near the slipspace portal device.
  • Reach - The planet Reach was the strategic and military HQ for the human United Nations Space Command. Located in the Epsilon Eridani star system, Reach was the biggest spaceport after Earth and served as the main fortress of defense during the 27 year Human-Covenant war. It was "glassed" by the Covenant shortly before the events of Halo: Combat Evolved. Its destruction is chronicled in the novel Halo: The Fall of Reach and was briefly seen in flashback at the start of Halo 2.
Originally colonized for its rich titanium deposits, Reach had mines throughout it running thousands of meters deep. UNSC High Command, Fleet Command and the Marine Corps had headquarters on Reach, as well as many primary Office of Naval Intelligence bases, which include CASTLE Base. CASTLE base was located on Reach underneath the Menachite Mountain range. This facility is where the SPARTANs first began their training. The facility was destroyed after the planet's fall to the Covenant in August 2552.
A secret area beneath Reach's surface contained a Forerunner artifact that was highly desired by the Covenant. The fact that this artifact was so valuable to them is perhaps the main reason anyone survived Reach at all, because the Covenant were fearful of destroying it and did not target a large area around the mountain range when they glassed the planet and wiped out the rest of its inhabitants.
The Covenant discovered the location of Reach after the battle of Sigma Octanus IV. Using a diversionary attack, they ensured human ships would scan for survivors after the battle then attached a spy drone onto the UNSC ship Iroquois. This drone took images of star constellations for several days before returning to a waiting ship by Slipspace, telling to the Covenant every place the human ship had been. They presumably scouted every system before finding Reach.
Reach was defended by more than a hundred UNSC ships, including the Hannibal, Pillar of Autumn, and the supercarrier Trafalgar. In addition to the fleet, Reach was defended by 20 Mark V Orbital Magnetic Accelerator Canon satellites (called SMAC, or Super MAC guns, and capable of propelling a round at 40% of the speed of light using superconducting magnets). Though the defenses were enormous, they couldn't hold back the Covenant onslaught, which was prepared to sacrifice an entire ship for the destruction of a MAC gun. The human fleet was decimated and its ground forces obliterated by the Covenant - the remaining ships, including the Pillar of Autumn, were forced to jump out of the system. After the Forerunner artifact on the surface was located, the Covenant "set fire" to Reach by "glassing" the planet with plasma. This presumably killed all remaining humans on the planet and scorched it to the point of being uninhabitable, save for the tiny section in which the search for artifacts continued.
After the events at Halo, the Master Chief returned to Reach on the captured Covenant flagship Ascendant Justice to search for any survivors of the SPARTAN team he sent down to defend the surface. Several SPARTANs had survived, along with a member of Reach's high command, Vice Admiral Danforth Whitcomb, and Dr. Halsey, the head of the SPARTAN project and a major human scientist. During the novel Halo: First Strike, the survivors of Reach returned to the small section of the surface that was not destroyed and recovered a Forerunner artifact that was buried deep in the surface. Several more Covenant ships were destroyed by the AI Cortana aboard Ascendant Justice, and the survivors escaped Reach to Slipspace.
Several experimental nuclear bombs (codenamed Novas, and featuring a lithium triteride casing that would boost the yield a hundredfold) were in development on Reach at the time of the Covenant attack. Vice Admiral Whitcomb rigged the bombs to explode ten days after the initial invasion, hoping that the Covenant would either take the bombs back to their homeworld for study or that when they exploded, the Novas would take out their foes on Reach. Due to the fact that just ten hours was left on the countdown when the Admiral and other survivors escaped,Covenant engineers deactivated the bombs, placing them in the storage bay of a Covenant supercarrier. Through a freak accident and more tampering of the engineers, at least one of the NOVA bombs detonated destroying a full Covenant battle group, a medium sized moon, and causing complete devastation of a nearby Covenant-held planet (described in Halo: Ghosts of Onyx).
  • ONI Castle Base - Located on Reach, this is the headquarters of Office of Naval Intelligence operations. A crystal of unusual characteristics with the ability to affect not only gravity but also space time is found in an ancient Forerunner cave buried deep underneath the Castle Base.
  • Jericho VII - The location of the battle at the beginning of the Fall of Reach, an Inner Colony, destroyed by the Covenant at the beginning of 2535. A large number of orphans from this planet enlist for the SPARTAN-III project.
  • Paris IV - Site of a major battle between the UNSC and Covenant forces; Sergeant Major A.J. Johnson is a veteran of the battle, where he supposedly contracted Boren's Syndrome, making him immune to Flood infestation.
  • Eridanus 2 – Eridanus 2 was the home planet of the SPARTAN-II supersoldier Master Chief John-117 along with some other future members of the SPARTAN-II special taskforce.
  • Harvest – A human outer colony "farm" planet, first target of the Covenant and glassed by them in 2525. A large number of orphans from this planet enlist for the SPARTAN-III program.
  • Sigma Octanus IV — A colony planet in the Halo series, significant because Installation 04's "coordinates" were discovered there on a shard of ancient rock.The planet is home to several million humans. It was also the location of two historic victories over the Covenant fleet. The first was a minor battle in which Commander Jacob Keyes destroyed three enemy warships causing the fourth to retreat. The next, larger fleet scale battle, was considered the biggest human victory since Admiral Cole retook Harvest. Its capital city is called Cote D'Azur, and was destroyed by a SPARTAN-II team using a Havok nuclear mine after being overrun with Covenant ground forces.
  • Coral - An inner colony which is glassed by the Covenant during the I Love Bees plot line. Formerly the site of a UNSC/ONI archaeological dig that uncovered a Forerunner structure.
  • Troy - A colony which had prior warning from an ONI Corvette, of an impending attack by the Covenant. Evacuation was slow and had barely begun when the attack occurred and the evacuation was covered up by ONI and the UNSC to prevent hostilities rising from the civilian populace against the UNSC.
  • Draco III - A world attacked by the Covenant sometime before the events of Sigma Octanus IV. Because they couldn't reach the location in time, the SPARTAN-IIs watched via satellite as Covenant Grunts and Jackals slaughtered a group of survivors.

The Covenant[]

Main article: Covenant (Halo)

A theocratic hegemony comprising many species of aliens led by a caste of religious leaders known as "Prophets". Engaged in a 27-year war with humanity and currently embroiled in a genocidal civil war, they serve as the initial and primary antagonists throughout Halo, Halo 2, Halo 3, and other Halo media. They see Humanity as a form of heresy against their relgion, and seek to destroy all of Mankind.

Covenant locations[]

  • High Charity - A giant station/city that serves as the capital of the Covenant alliance and the home of its theocratic leaders the prophet Hierarchs. It exists as a massive mobile space station with a dome-shaped surface. Inside it harbors an entire city powered by a Forerunner ship touching the roof of the station in the center of it. It can travel through slipspace like any other Covenant ship. As of the end of Halo 2, Flood have hijacked a human ship (In Amber Clad) and infested High Charity, and the Forerunner ship has separated itself, with the Master Chief SPARTAN-117 aboard. High Charity was destroyed as it crash landed on The Ark in an attempt to spread the flood infestation further.
  • Joyous Exultation - A Covenant-held world that was severely damaged by Admiral Whitcomb's NOVA bomb during the events of Halo: Ghosts of Onyx.
  • Unyielding Heirophant - A massive control and support station that was assisting a Covenant armada preparing to travel to Sol. The Master Chief and a handful of his fellow Spartans boarded the station and triggered a meltdown of its reactors. With the station about to explode, Admiral Danforth Whitcomb and Lieutenant Haverson, aboard a captured Covenant flagship known as the Ascendant Justice, lured the remaining Covenant ships close enough to be consumed by the detonation.
  • Sanghelios - the Elite (Sangheili) homeworld. There is a War College in the Iruiru region of Yermo, Sanghelios. It is likely to be home to a large civilian population of Elites (Sangheili) and possibly some form of defence force (most likely a large fleet). Sanghelios is also likely to be the location of an ongoing battle due to Covenant civil war.[1] Because of the Elite's secession from the Covenant, it is probable that Sanghelios became the capital of the Covenant Separatists.
    • Locations
      • Yermo
      • Iruiru
    • Notable Residents
      • Usze ‘Taham
      • Toha ‘Sumai
      • Rtas 'Vadum

The Forerunners[]

Main article: Forerunner (Halo)

An ancient, technologically advanced and mysterious race that built the Halos and many other artifacts and structures throughout the galaxy. They died out millennia ago after a three-hundred year war with the Flood. In desperation, the Forerunners activated the Halo rings, thus killing most of their race and all potential food sources for the Flood. The Forerunners are also the ancestors of the human race, as revealed in Halo 3.

Forerunner locations[]

  • Threshold - The gas giant that Installation 04 (or Alpha Halo) orbited before its destruction in the events of Halo: Combat Evolved. There is a multiplayer map set on its moon Basis, and two campaign levels set on a gas mine in Threshold's low orbit, part of which had been converted by the Forerunners to research the Flood during the early years of their war.
  • Substance - The gas giant planet that Installation 05 (Delta Halo) orbits.
  • Halos - Seven titanic ring-shaped constructs that serve as weapons of last resort to contain the Flood. Together the Halos possess the power to destroy all sentient life in the galaxy. They are centrally controlled at the Ark, which can also rebuild damaged Halos. The fourth of seven was destroyed in Halo, rebuilt by the Ark in Halo 3, and subsequently destroyed.
  • The Ark - Was thought to be located in the vicinity of New Mombasa on Earth. This proves to be inaccurate as the structure buried there deep underground is actually a gateway to the Ark which resides in deep space (218 lightyears away from the Milky Way center, outside of the effective range of the Halo network and probably conventional Faster-Than-Light travel [hence the biblical reference]) and is a mechanism capable of firing the entire Halo network. Its original purpose was a storage location for all "indexed" species as well as Forerunner survivors during the firing of the Halos. The Ark is capable of ordering repairs and reconstructions of damaged HALO rings. Was destroyed by John-117, the Arbiter, Cortana and Sergeant Johnson at the end of Halo 3.
  • Onyx - An artificial "shield world" constructed by the Forerunners, formed from literally trillions of Sentinels interlocked into a planetary body. Served as the training ground for the SPARTAN-III program. At the core of the planet is a Slipspace rift that connects to a compressed Dyson Sphere isolated from normal space-time, which serves as a "bomb shelter" of sorts against the activation of the Halos.

The Flood[]

Main article: Flood (Halo)

A virulent, parasitic alien race that absorbs individuals with sufficient mass and intelligence as part of itself. The Flood appears to be a hive or communal mind, ultimately expressing itself as a Gravemind. The Flood spores mutate the host's body into a combat form, which if sustaining sufficient damage becomes a carrier form, an incubator for more spores. A separate form available to advanced groups of Flood which already have an established Gravemind is the Pure Form, which can mutate between an insect-like base, a sniper form, and a "tank" form. The Flood is considered a parasite and dangerous enemy by both the Covenant and UNSC.


Early Conflicts[]

In the years 2160-2200, various governments, and factions fought for control of Earth and its first Colonies. As overpopulation and unrest on Earth mounted, new political movements formed including the Jovian Frieden and Koslovics led by Vladimir Koslov, resurgences of Fascism and Neo-Communism which waged the Interplanetary, Rain Forest Wars Campaign and Mars clashes and were defeated by the United Nations Space Command.

The Human Colonization of the Orion Arm[]

In the years 2170-2291, the United Nations Space Command (UNSC) successfully developed humanity's first faster than light drive, the Shaw-Fujikawa Translight Engine. For the first time in history, the rapid colonization of other worlds is made possible. By 2390, 210 worlds had been occupied by humans, and were being actively terraformed to suit man's needs. These worlds are to become known as the Inner Colonies. By 2490, the UNSC's fledging Interstellar Empire had expanded to between 800 to 1000 planets throughout the Orion Arm of the Milky Way Galaxy. During this period, the planet Reach becomes one of the two headquarters of the UNSC military and government (the other was Earth itself), and is destined to become the most heavily fortified world under human control and the Inner Colonies became the heart of the UNSC government.

In addition, there were numerous small-scale brushfire wars with rebels in the Outer Colonies, which served to tax UNSC resources.

At the time of 2517, The UNSC was facing extremely low morale due to piracy and the Brushfire Wars. In order to remove the rebellion without a significant sacrifice of human life, Dr. Catherine Halsey moved forward with the SPARTAN-II Project. 75 gifted children were abducted and replaced by flash-clones, and drafted into the UNSC. The children went through rigorous training exercises. Later in life, they were physically augmentated- these alterations were so radical and dramatic that a sizable portion of the highly-trained soldiers died or were physically deformed. The surviving soldiers were gifted with increased bone strength, increased sensory awareness, faster reflexes, and musculature density enhancements. Code-named SPARTANs, these genetically enhanced troops were trained from the age of six into a life of battle, and would become a great asset against any military insurrection.

On September 12, 2525 the SPARTANs were sent to the Eridanus II system to capture Colonel Robert Watts, a rebel leader. The mission was successful, and therefore significantly reduced the pirate threat. However, the role of the SPARTANs did not end with the capture of Robert Watts, since they were needed for the new war against the Covenant.

Shortly after the capture of Colonel Robert Watts, the SPARTANs became an elite unit of the UNSC's military ground forces. Before engaging the Covenant, all SPARTANs were given special armor designated MJOLNIR, which, in layman’s terms, can increase their strength, speed, and reaction time. They were the only ones who could wear it, as those without the proper body training or biological augmentations killed themselves with strength-enhanced convulsions.

Human-Covenant War[]

Covenant over reach

A Covenant Fleet glassing Reach.

The outbreak of outright war between the humans and Covenant developed in 2525, twenty seven years before the events of Halo: Combat Evolved. The UNSC was totally surprised by the first contact with the alien alliance. The Covenant declared a religious crusade against the humans, and began to eradicate human colonies.

Because of the Covenant's heretical perspective of humanity, the Covenant engages in a practice known as "glassing" using their plasma weaponry. This tactic, as the name implies, burns the surface of the planet at very high temperatures, leaving the surface as nothing more than an expanse of cracked and charred glass and eradicating anything and everything. Between the Covenant's extreme orbital bombardment campaigns and the sheer technological and numeric superiority, it was difficult for the UNSC to find a victory.[2]

Though the Human forces fought vigorously, their inferior technology and numbers meant that any victory, small or large, was hardly guaranteed. In space, battles were often so one-sided that dozens of UNSC ships would be wiped out for every handful of Covenant ships. Once the human orbital defenses (naval vessels called to the system's defense, or in the case of Reach, orbital MAC guns) are destroyed, the Covenant would land massive numbers of soldiers and eradicate the planet's inhabitants. Once the vast majority of the colonists and soldiers alike were killed, the Covenant would recall their ground forces and glass the planet.

Using their superior weaponry, the Covenant was able to defeat the Human colony worlds one by one until they finally reached the first major inner colony, Reach, twenty-seven years later, having skipped some small remaining outer colonies. Though the colony was defended by MAC guns, the Covenant were able to destroy the station's planetside generators, rendering the defense grid useless; they then proceeded to glass the planet (the only documented case where a planetary invasion did not precede a planet's glassing) .[3] It is after this showdown that the player is introduced into the story as MCPO Spartan 117 on the UNSC Pillar of Autumn, which is fleeing Reach; this is the beginning of Halo: Combat Evolved.

Discovery of Installation 04[]

The Covenant armada around Reach pursued the Pillar of Autumn, tracking the ship through slipspace.[4] Upon exiting slipspace, both the humans and Covenant encountered the Forerunner structure Halo around the gas giant Threshold. The Covenant's superior slipspace technology actually allowed the Covenant to arrive at the Pillar of Autum's destination before the Pillar of Autum, supposedly to lie in wait to destroy the USNC ship, but when they emerged from slipspace, the Covenant discovered the Forerunner artifact and began exploring it. We don't know how much time the Covenant had to explore before the USNC ship arrived, but this explains why the Covenant are already all over the Halo.

Due to a Prophet aboard the lead Covenant cruiser not wanting to damage the "sacred ring", human survivors from the Pillar of Autumn were able to land on the surface and coordinate a guerilla resistance.[5]

The Covenant similarly deployed ground troops to engage the Humans, while trying to find Halo's Control Room to activate the station.[6] The human forces learned of the Covenant's intentions, however, with the Master Chief reaching the Control Room before the Covenant.

At the same time, by accident or by design[7] the Covenant released The Flood, which rapidly infected human and Covenant hosts. The Covenant were forced to divert their attention to stemming the spread of the Flood, leading a special operations team to a damaged cruiser in order to prevent it from falling into the Flood's control. In the ensuing chaos, the Master Chief detonated The Pillar of Autumn's fusion reactors and destroyed Halo, a major setback for the Covenant; in addition to the sacred relic being destroyed, the Covenant suffered grievous casualties. A few Covenant escaped, and the fleet commander "responsible" for the act of heresy was stripped of his rank, later becoming the Arbiter.

According to the novel Halo: First Strike, shortly after the defeat at Halo, the Covenant had amassed a large fleet allegedly to assault Earth. It is explained in the I Love Bees alternate reality game that the Covenant discovery of Earth was accidental; A deviation of the Cole Protocol by the Apocalypso allowed a Covenant AI, the Pious Flea, to enter Earth's space and transmit its location.

When the ship tumbled into real space and crashed on the moon, the Pious Flea sent a message to the Covenant military command. This message included detailed information about Earth, in which system the planet was located, and the presence of Forerunner artifacts on the planet's surface.

Covenant Attack on Earth[]

Shortly after the destruction of a large Covenant armada by Admiral Danforth Whitcomb, the High Prophet of Regret leads a small fleet of fifteen ships[8] to Earth to locate a Forerunner artifact known as "The Ark". Though outgunned by the UNSC's new orbital defense grid of MAC guns, the Prophet of Regret's flagship manages to break through the human defenses to New Mombasa. The Covenant ground troops quickly spread through the city, destroying both military and civilian resistance, but a counterattack drove them back. Regret's cruiser jumps into Slipspace from within the city, destroying most of Mombasa.

A single Human ship, the In Amber Clad, followed Regret through his own Slipspace rupture to Delta Halo. With the orders "Find out why Regret came to Earth; why he came here," the Master Chief was sent with a complement of Orbital Drop Shock Troopers to Delta Halo's surface. Led by the Chief, the Humans forced their way through Regret's forces until they had reached the Prophet himself. At that moment, High Charity, having learned of Delta Halo, arrived and launched multiple waves of Phantom dropships to aid Regret, but were recalled by Truth. The Chief assaulted and killed Regret, and the Covenant fleet bombarded the temple attempting to kill the Master Chief. The Master Chief narrowly escaped, aided by a Flood entity called Gravemind.

Originally, the Covenant had been unaware of the Index's importance until the Arbiter recovered the Monitor of the first Halo while destroying a heretical sect. The Monitor, known to the Covenant as an Oracle, told the Prophets of the Index and the Arbiter was sent to retrieve it. The mission was complicated though by the unforeseen release of the Flood on Installation 05. Despite this, the Arbiter successfully reached the Library and prevented the humans from claiming the Index. Just as Miranda Keyes claimed the index, and the Arbiter stole it from her, kidnapping her and Sgt. Johnson. However, the Index was stolen from the Arbiter by the Brute Chieftain Tartarus, who under the Prophets' orders then attempted to kill the Arbiter. With the Index secure, the Prophets then ordered the Brutes to begin eradicating the Elites, thus starting the Covenant Civil War (see below).

Following the Flood infestation of High Charity at the end of Halo 2, the High Prophet of Truth led the remaining loyalist fleet to Earth to complete what the previous mission to Earth had not. Little did he know that Spartan 117, Master Chief, had stowed away with him. By the time Truth arrived at Earth, a full-scale war in space and on the ground was underway between UNSC and Covenant fleets, and in Halo 3 the Covenant are seen to have gained a slim military victory on Earth after two weeks of fighting, such that they could focus their attentions on putting troops and the Forerunner Dreadnaught in Africa.

Covenant Occupation of Earth[]

When the Master Chief arrives back on Earth, via falling from the sky, he discovers that the Arbiter and the Elites have joined forces with the humans in an attempt to stop the Covenant who have gained near full control of the planet. However, the Covenant focus all their attention on one location in the ruins of New Mombasa. Commander Miranda Keyes immediately knows that they have discovered the Ark and sends the Master Chief, Marines, and the Arbiter to their location in an attempt to stop the activation of the Halo Rings. They fail to arrive in time as the Prophet of Truth activates the Ark. It is then discovered that the construct they activated was not the Ark, but was a gateway to the Ark.

Before the Elites and Humans could respond to this discovery and pursue the Prophet of Truth, the Flood arrive from a slipstream rift and crash land on Earth. While the Elites and the Arbiter were destroying the flood, the Master Chief investigated the Flood infested ship and found a message from Cortana, who was still trapped by the Gravemind. The Master Chief was evacuated off the surface and the Elites glassed the area (presumably half the continent) to prevent the Flood from spreading. Most of the remaining human forces, the Elites, and 343 Guilty Spark traveled to the Ark via slipspace portal above the gateway.

By March 3, 2553, the Human-Covenant war was over, with the remaining Covenant forces and Flood destroyed on or around the Ark. Elites and the Humans were at peace, and Humanity was rebuilding.


  2. "Halo Story Timeline". Retrieved February 23. 
  3. see Halo: Fall of Reach
  4. Cortana: ...As for tracking us all the way from Reach, at light speed my maneuvering options were limited.
  5. See Halo: The Flood
  6. Cortana: One moment Sir. Accessing Covenant battlenet. (Pause) According to the data in their networks, the ring has some kind of deep religious significance. If I'm analyzing this correctly. ..they believe that Halo is some kind of weapon. One with vast, unimaginable power. [...] they must be looking for Halo's control room.
  7. Bungie, ed. (2004) (in English). Halo 2 Instruction Manual: Secret Transmission. Microsoft Game Studios. pp. 2. 
  8. Cortana: Fifteen Covenant capital ships, holding position just outside the killzone.

External links[]