Editing Human-Covenant War

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{{Infobox Military Conflicts
|name        = Human-Covenant War
|image       = [[File:Halo Wars Marine BR.jpg|400px]]
|begin       = February 3, [[2525]]<ref>[[First Battle of Harvest]]</ref>
|end         = December [[2552]]
|place       = The Orion Arm of the [[Milky Way|Milky Way galaxy]] (except for the [[Battle of Installation 00]], which took place outside of the Milky Way).
|result      = [[UNSC]] Pyrrhic victory, [[Covenant Separatist]] victory<ref>''[[Believe]]'', ''[[Museum]]''</ref> 
*The [[Covenant]] collapses
*Both the [[Ark]] and [[Installation 04B]] are believed to be destroyed or heavily damaged
*[[Flood]] threat is believed to be neutralized
*[[Human]] population reduced considerably
|side1       = *[[United Nations Space Command]]
* [[Covenant Separatists]] (After the [[Great Schism]])
* [[Forerunner]]
|side2       = *[[Covenant Empire]]                 
**[[Covenant Loyalists]] (After the [[Great Schism]])
|commanders1 = *[[UNSC High Command|HIGHCOM]], [[Colonial Military Administration]]
**[[Fleet Admiral]] [[Terrence Hood|Lord Terrence Hood]]
**[[Fleet Admiral]] [[H.T. Ward]]
**[[Fleet Admiral]] [[Harper]]
**[[Admiral]] [[Roland Freemont]]†
**[[Admiral]] [[Carl Patterson]]†
**[[Admiral]] [[Preston Cole]]† (MIA assumed KIA)
**[[Admiral]] [[Margaret O. Parangosky]]
**[[Admiral]] [[Michael Stanforth]]†
**[[Admiral]] [[Danforth Whitcomb]]†
**[[Major General]] [[Nicolas Strauss]]
**[[Captain]] [[Jacob Keyes|Jacob Keyes]]†
**[[Colonel]] [[James Ackerson]]†
**[[Captain (Navy)|Captain]] [[James Gregory Cutter]]
**[[Commander (UNSC)|Commander]] [[Miranda Keyes]]†
*[[Covenant Separatist]] leaders
**[[Imperial Admiral]] [[Xytan 'Jar Wattinree]]†  (post-[[Great Schism]])
**[[Arbiter]] [[Thel 'Vadam]] (post-[[Great Schism]])
**[[Ship Master]] [[Rtas 'Vadum]] (post-[[Great Schism]])
**[[Fleet Master]] [[Voro Nar 'Mantakree]] † (post-[[Great Schism]])
*[[Forerunner]] [[Monitor]]s
**[[343 Guilty Spark (Monitor)|343 Guilty Spark]] † (turned rogue)
|commanders2 = *[[High Prophets]]†
**[[High Prophet of Truth]]†
**[[High Prophet of Regret]]†
**[[High Prophet of Mercy]]†
*The Council of the Covenant
*[[Chieftain of the Jiralhanae]] [[Tartarus]]†
*[[Rtas 'Vadum|Special Operations Commander Rtas Vadumee]] (pre-Great Schism)
*At least 3 Arbiters
**[[Ripa 'Moramee]] †
**[[Thel 'Vadamee]] (pre-Great Schism)
**Arbiter of [[Battle of Jericho VII]]†
|forces1     = *[[United Nations Space Command|UNSC]] [[United Nations Space Command Defense Force|Armed Forces]]
*[[Covenant Separatist]] Armed Forces (post-[[Great Schism]])
*[[Forerunner]] [[Sentinels]]
|forces2     = *[[Covenant]] Armed Forces
|casual1     = *Approximately 23 billion civilian and military casualties.<ref name=HE:PH>'''''[[Halo: Evolutions - Essential Tales of the Halo Universe|Halo: Evolutions]]:''' [[Palace Hotel]]'', page 351</ref>
*Unknown Separatist force killed, likely in the thousands to hundreds of thousands due to late entry into the war.
|casual2     = *Heavy casualties for all races
**Destruction of Covenant Holy City ''[[High Charity]]'' and the devastation of [[Joyous Exultation]]
**Most of the Loyalist forces
**At least 2 Arbiters
**At least one Chieftain of the Jiralhanae
**[[Prophet of Regret]]
**[[Prophet of Mercy]]
**[[Prophet of Truth]]
}}
{{Quote|Oh, death was never an enemy of ours!<br>We laughed, knowing better men would come, and greater wars:<br>When each proud fighter brags<br>He wars on death, for lives: not men, for flags.|"[[The Next War]]"}}

The '''Human-Covenant War''', also known as '''The Great War''', was a major interstellar conflict pitting the [[Unified Earth Government]] and its [[United Nations Space Command]] against the [[Covenant Empire]] during the mid-26<sup>th</sup> century between February 11, 2525 and March 3, 2553. There were two additional factions of the conflict; The [[Flood]] and a small number of surviving Forerunner constructs. Both additional factions proved to be invaluable to the efforts of humanity, as the information taken from [[Forerunner]] constructs and the Flood invasion of ''[[High_Charity_(Structure)|High Charity]]'' were helpful in [[Great Schism|splitting the Covenant apart]] in October of [[2552]].

The war was instigated by the Covenant, whose [[Prophet]]s discovered that humans were directly related to the [[Forerunner]]s. In order to keep the Covenant intact, war was declared against humanity. Over the next few decades, the Covenant, with superior firepower, tactics (debatably), numbers and technology, overpowered humanity on hundreds of worlds, including heavily defended strongholds such as [[Reach]]. The Humans would only win scattered and costly victories.

The conflict was closely connected with, and the cause of, the [[Covenant Civil War]], both of which resulted in the final defeat of the Covenant Loyalists and [[Flood]]. The official cessation of hostilities occurred on March 3, [[2553]]. The war was incredibly costly to both sides, with over twenty-three billion humans and likely hundreds of millions (potentially billions) of Covenant killed during the hostilities and further heavy casualties during the Flood plague. The war ultimately lasted for a total of twenty-eight years.
== History ==
===Declaration of War (2525)===
{{main|First Battle of Harvest}}
[[File:SSgt Avery Johnson, UNSC Marine Corps.JPG|thumb|200px|Staff Sergeant Johnson leading Colonial Militia during the Covenant invasion of Harvest.]]
[[Humanity]] and the Covenant first came into direct contact in February 3rd [[2525]], when a [[Kig-Yar]] Frigate, the ''[[Minor Transgression]]'', discovered a human ship that had dropped out of slipspace due to a problem with the [[Shaw-Fujikawa Translight Engine]]. The Kig-Yar raided that ship and another one. The Harvest shipping operations AI, Sif, found out about the raids as a result of the distress beacon from the ships (although she and an [[Jilan al-Cygni|undercover ONI spook]] on Harvest thought that Insurrectionists, not aliens, were behind the raids). The spook set a trap for the Kig-Yar which resulted in a [[Skirmish Over Harvest|minor skirmish]] between [[Staff Sergeant]]s [[Nolan Byrne]] and [[Avery Johnson|Avery Johnson,]] and the Kig-Yar privateers. When the Covenant returned with another ship and a contingent of Brutes, the UNSC proposed a meeting (via pictogram) to trade. The Covenant met the UNSC on Harvest, but were only interested in claiming the relics that the [[Luminary]] had detected on Harvest, completely oblivious that the humans were the "relics" in question. The meeting was botched after [[Osmo]], a member of the [[Colonial Militia]], -- was attacked by a nervous [[Grunt]] -- who was part of a second Covenant force sent to look for the relics. As a result, a firefight erupted between the two groups and the Covenant retreated back to their ship.

The Prophets declared Humanity to be an affront to their gods (supposedly because Humans inhabited and "defiled" areas which were once Forerunner), and called for a crusade against the Human species. This "crusade" would eventually turn into mass [[Wikipedia:Genocide|genocide]].

The campaign to exterminate Humanity was an attempt by the Prophets to keep their power, under the disguise of a holy crusade. The Prophets found out that the Forerunner objects that the Luminary revealed on Harvest were actually Humans (which the Prophets interpreted as meaning that the Humans were descendants of the Forerunner, or possibly surviving Forerunner). Initially, the Covenant interpreted the glyph from the luminary as "Reclamation". Startlingly, the Forerunner AI [[Mendicant Bias]] revealed that the interpretation was wrong: the glyph meant "Reclaimer". The Prophets Regret and Truth realized that if the Humans were actually Forerunners, then it was possible to be left behind when the Great Journey occurs. This stood in contradiction to the Covenant religion, which held that no one would be left behind in the Great Journey. The Hierarchs, recognizing that this truth would destroy the Covenant, declared war on Humanity, hoping the truth would perish with their newly-declared foe.

The first battle of the war was the extended though one-sided ground battle which took place on Harvest, in which the UNSC managed to delay the Covenant long enough to evacuate many of Harvest's civilians. Eventually, the Covenant used their capital ships to [[glass]] the planet's surface.

===Open War (2525-2552)===
[[File:Outcome of Second Battle of Harvest.png|thumb|200px|Cole's fleet destroys the Covenant ship in the Second Battle of Harvest.]]
From that point on, the Covenant continued to attack and destroy the Humans where ever they were found, using their [[Luminary|Luminaries]] to find Human worlds. Though the UNSC forces fought bravely, their inferior technology and numbers meant that even a close victory was far from guaranteed. The Covenant also had an advantage in that they didn't need to fight planet-side to destroy the enemy; their ships simply needed to destroy the Humans' space-borne defenses and any other threats around the planet, and then reduce the planet's surface to glass with orbital plasma bombardments. The few victories achieved by the UNSC were due to special tactical maneuvers, as human missiles and magnetic acceleration weapons were unable to compete with Covenant energy shields and plasma torpedoes. Over twenty-seven years, the Covenant whittled down the UNSC planet by planet.

Realizing the threat posed to humanity by the Covenant, the UNSC [[Colonial Military Administration]] gave [[Vice Admiral]] [[Preston Cole]] the command of the then-largest fleet in human history with orders to retake Harvest. Cole [[Second Battle of Harvest|retook Harvest]] in [[2526]], and then spent five years chasing the Covenant around the [[Outer Colonies]], fighting them and scoring victories at [[Alpha Aurigae System|Alpha Aurigae]], [[XI Boötis A System|XI Boötis A]], and [[Groombridge-1830]]. Meanwhile, the Covenant returned to Harvest, determined to recapture the planet. This led to a five-year long [[Harvest Campaign|series of engagements]] on Harvest between the Covenant and the UNSC.

===The Apex and the Arbiter (2531)===
[[File:Vlcsnap-126257.png|thumb|250px|left|The [[Prophet of Regret]] converses with the [[Ripa 'Moramee|17th Arbiter]] on the destruction of the human race.]]

Despite their major numerical and technological advantages over humanity, by [[2531]], the Covenant High Prophets had realized that the task of destroying an entire sapient species had a logistical burden beyond anything that the [[Covenant Military]] could muster without leaving Covenant space defenseless.<ref>''[[Halo Wars]]'' level "[[Scarab (Level)|Scarab]]", first cutscene</ref> In spite of the UNSC's inferiority in comparison to the Covenant, the Prophets apparently considered their armed forces to be powerful enough to pose a threat to the Covenant proper. The [[Prophet of Regret]] dispatched an [[Ripa 'Moramee|Arbiter]] to Harvest to claim a Forerunner [[Relic (Structure)|artifact]] buried under the north pole of Harvest.

Preston Cole counter-attacked by leading a fleet composed of the {{UNSCShip|Spirit of Fire}} and the {{UNSCShip|Prophecy}} back to Harvest after receiving a message from an [[ONI]] [[UNSC Prowler|Prowler]]. The battle was a human victory despite major casualties. Upon discovering that the Covenant, under the command of 'Moramee, had excavated Forerunner artifacts in the northern polar region, [[Captain]] [[James Cutter]] deployed ground forces to remove the Covenant occupation. After a heated fight on the surface, the UNSC forces were able to examine the artifact, apparently some kind of star map, and realized that information from the map had led the Covenant to another UNSC colony: [[Arcadia (Planet)|Arcadia]].

[[File:ApexBattleImage.png|thumb|250px||right|The {{UNSCShip|Spirit of Fire}} engages a Covenant [[Covenant Destroyer|destroyer]] in the Flood-Controlled Shield World.]]

As predicted, the Covenant [[First Battle of Arcadia|followed the information]] from the artifact to Arcadia. The Covenant wished that the planet would contain more Forerunner artifacts for them to claim, and while they only found a [[Arcadia Forerunner Ruins|complex of ruins]], information garnered from them led them to a [[Shield World (Halo Wars)|Shield World]]. The ''Spirit of Fire'' followed and removed the Covenant presence from the planet. However, 'Moramee's capture of an [[Ellen Anders|important civilian researcher]] forced Captain Cutter to pursue the Covenant to the newly discovered Shield World without reinforcements.

On the Shield World, the crew of the ''Spirit of Fire'' eventually discovered that the Covenant needed Professor Anders to activate [[the Apex]] and claim the huge fleet of [[Unnamed Forerunner Starship|Forerunner starships]] held there. A group of Marines, together with SPARTAN-II [[Red Team]], rescued the researcher and destroyed the Shield World. The Arbiter was also killed by [[John Forge]] during the battle though the Prophet of Regret escaped.

===SPARTAN-III (2531)===
{{Main|SPARTAN-III Program}}
Despite the well-publicized victory at Harvest, the UNSC was already on the way to losing the war. A number of colonies had already been glassed by the Covenant or abandoned, including [[Eridanus II]], [[Dwarka]], and [[Chi Ceti IV]]. The UNSC's sole hope apparently lay with the [[SPARTAN-II Program]], a secret program to create super soldiers originally to combat [[Insurrectionist]]s. However, there were not enough Spartans to turn the tide of the war in favor of humanity. Recognizing this, the Office of Naval Intelligence authorized the creation of the [[SPARTAN-III Program]]. The brainchild of [[Colonel]] [[James Ackerson]], these Spartans would be trained with a greater emphasis on stealth and teamwork, and would be sent on missions against high-priority targets that would be impossible even for elite units.

===Crisis (2534-2535)===
[[File:CP armor.png|thumb|200px|A member of Gray Team at the [[Battle of the Rubble]].]]

With majorities of the Outer Colonies glassed or abandoned, the UNSC faced an economic crisis as some of their [[Agriculture World]]s had been destroyed, leading to food shortages. On [[Charybdis IX]], food riots broke out. Meanwhile, Covenant forces began to encroach on the [[Inner Colonies]]. In response, the UNSC issued [[United Nations Space Command Emergency Priority Order 098831A-1]], "The Cole Protocol". It stated that no UNSC vessel may lead the Covenant to Earth or any other human population center. Furthermore, all movement through space was restricted to [[UNSC Navy]] vessels. [[Insurrectionist]] attacks increased in the face of what they saw as a removal of their right to freedom of movement. Another development was the discovery of Insurrectionists using Covenant weapons modified for human use. The UNSC saw this as a threat to security as the weapons may have been carrying Covenant homing beacons. The Covenant saw it as heresy that humans would modify their weapons, and the [[Prophet of Regret]] dispatched [[Thel 'Vadam|Thel 'Vadamee]] to destroy the source of the modified weapons: [[The Rubble]].

Fleeing from the [[Battle of Charybdis IX]], the {{UNSCShip|Midsummer Night}} chased an Insurrectionist freighter to the Rubble and discovered that the Insurrectionists there had actually formed an alliance with a colony of [[Kig-yar]]. The Jackals were supplying the weapons and the Insurrectionists were modifying them. The crew of the ''Midsummer Night'', including its captain, [[Lieutenant (UNSC)|Lieutenant]] [[Jacob Keyes]], were captured, but later escaped and helped SPARTAN-II [[Gray Team]] and the Rubble's citizens stop an assault from the Kig-yar leader, [[Reth]], and 'Vadamee's forces. It later transpired that the [[Prophet of Truth]] had ordered the Kig-yar to ally with the humans so that they could discover the location of [[Earth]] from stolen navigation data of through tracking devices in the weapons. Through this, the Covenant found two more worlds to attack.

By the time of the [[Battle of Jericho VII]] in 2535, most of the Outer Colonies had been destroyed.

===Continuing War (2536-2551)===
[[File:Origins ii Human-CovenantWar.jpg|thumb|right|225px|Humanity, heavily out-gunned, lost much ground to the Covenant.]]
For fifteen years, the war continued in much the same way as before; minor, costly victories on the ground for UNSC forces, but total Covenant space superiority. The UNSC managed to deal a heavy blow to the Covenant in 2537 with the destruction of the Covenant manufacturing plant [[K7-49]] in [[Operation: PROMETHEUS]], and again during the [[Siege of the Atlas Moons]] in the same year. However, these victories were offset by the loss of [[New Constantinople]], the loss of its colonies at [[Leonis Minoris]], and the total destruction of the force of SPARTAN-IIIs sent to destroy the Covenant base.

Throughout the 2540s, the UNSC was dealt ever greater blows with the death of the SPARTAN-II [[Sheila]] during the [[Battle of Miridem]] in 2544, and the [[Second Battle of Arcadia]] and the [[Siege of Paris IV|loss of Paris IV]] in 2549. One of the UNSC's success was [[Operation: TORPEDO]] in 2545, and even then it was a Pyrrhic victory at best.

Of the few wins in the 2540's for the UNSC, one of the most significant, and strategically advantageous, was the [[Battle of Psi Serpentis]] in 2543. This battle became colloquially known as Admiral Cole's last stand due to the presumed death of [[Preston Jeremiah Cole|Admiral Preston J. Cole]]. In addition to the alleged death of Cole, over 300 [[Covenant Empire|Covenant]] vessels, two fleets worth, were completely vaporized when [[UNSC]] [[Nuclear weapon|nuclear missiles]] detonated inside the atmosphere of [[Viperidae]], a super massive gas giant. This detonation spurred spontaneous fusion at the core of Viperidae, temporarily turning the super gas giant into a brown dwarf star. Cole's achievements in this battle alone were only rivaled by the [[Operation: FIRST STRIKE|destruction]] of the ''[[Unyielding Hierophant]]'' and the actions of [[John-117|Spartan-117]] throughout the course of the war. A painting depicting the battle, titled "[[Admiral Cole's Last Stand]]" was created and by [[2552]], it hung on the wall of the [[HIGHCOM Facility Bravo-6]] on [[Sydney]], Earth.<ref>'''[[Halo: Evolutions]]''' - ''[[The Impossible Life and the Possible Death of Preston J. Cole]]'', pages 472-485</ref>

Towards what appeared to be the obvious end of the war by 2552, the Office of Naval Intelligence was resigned to the fact that humanity may only have months left before the Covenant destroyed the remaining Inner Colonies and moved on against Earth.

===The Final Year (2552)===
The last year of the war saw humanity's largest defeat since the war's beginning, but also saw several of their greatest victories, coupled with the destruction of the Covenant as a galactic power. On [[Sigma Octanus IV]], the Covenant were [[Battle of Sigma Octanus IV|defeated]]. On the ground, the SPARTAN-IIs secured a Forerunner [[Sigma Octanus IV Artifact|artifact]] covered in symbols that the Covenant tried to transport out of [[Cote d'Azur]]. However, in space, the Covenant placed a [[Spy Probe]] on the [[UNSC Iroquois|UNSC ''Iroquois'']], which led the Covenant to the UNSC's stronghold and main headquarters, [[Reach]]. 

The [[Fall of Reach]] that followed had staggering losses for both sides, but ended in a Pyrrhic Covenant victory. The ''[[UNSC Pillar of Autumn|Pillar of Autumn]]'' was among the surviving UNSC ships which fled the battle, and made a somewhat blind jump, as described by Cortana saying that she realized that the symbols on the retrieved artifact from Sigma Octanus IV were in fact very old star charts and were coordinates to the Forerunner ring world of [[Halo]], being chased by a dozen Covenant warships.

===The Tide Turns (2552-2553)===
[[File:Battle of Reach.jpg|thumb|right|300px|The [[UNSC Pillar of Autumn|''Pillar of Autumn'']] pushes through the Covenant blockade and escapes [[Reach]].]]

The Covenant's first costly defeat was on and around [[Installation 04]]. Here, the Human survivors from the [[Halcyon-class cruiser|''Halcyon''-class cruiser]], the ''Pillar of Autumn'', managed to form an effective and surprising resistance to the Covenant. Unwilling to risk damaging the [[Halo|sacred ring]], the Covenant was forced to fight the Humans on Halo's surface rather than using its usual bombardment tactics. The Covenant found the Humans uncannily adapted to Halo's environment and very adept at fighting on the surface, with Human firearms and vehicles proving effective despite their technological inferiority. Unable to counter the guerrilla tactics employed by the Humans, the Covenant was soundly defeated in numerous raids, including one instance when the Humans boarded their grounded cruiser, the ''[[Truth and Reconciliation]]'', and successfully escaped with a group of captives, including the captain of the ''Pillar of Autumn'', [[Captain Jacob Keyes]]. The battle on Halo then suddenly took a turn for the worst for both sides when the Covenant accidentally released an ancient and deadly parasitic race called the [[Flood]]. The Flood, having been imprisoned within Halo for many thousands of years, spread quickly throughout the ring, killing or assimilating every unsuspecting human and Covenant in their path.  

During the course of the battle, the SPARTAN-II known as the [[John-117|Master Chief]] discovered the true nature of Halo and proceeded to detonate the crashed ''Pillar of Autumn's'' engines, destroying the ring, and escaped, much to the Covenant's horrified dismay. The destruction of Halo and the later loss of the [[flagship]] ''[[Ascendant Justice]]'' to the surviving UNSC forces led to [[Supreme Commander]] [[Thel 'Vadamee]] being disgraced and demoted before being branded with the [[Mark of Shame]], leaving him dead in the eyes of the [[Sangheili]]. Only the intervention of the [[Prophet of Truth]] prevented 'Vadamee's certain execution. He was instead given the rank of [[Arbiter (Rank)|Arbiter]] and sent to quell a [[Heretic]] uprising that had taken root on the [[Gas Mine]] around [[Threshold]].

[[File:UNSC Home Fleet.JPG|thumb|left|250px|The [[UNSC]] [[UNSC Home Fleet|Home Fleet]] prepares to engage the [[Covenant Navy]].]]

Shortly after the defeat at Halo, the Covenant had amassed a large [[fleet]] that appeared to be intended to assault [[Earth]]. The Covenant discovery of Earth was an accident after the ''[[Pious Flea]]'' had been intercepted by the UNSC stealth ship ''[[Apocalypso]]''. After retrieving a Forerunner artifact, the ''Apocalypso'' made a [[Slipspace]] jump directly to Earth. When the ship tumbled into real space and crashed on the moon, the ''Pious Flea'' sent a message to the heart of the Covenant military, containing reconnaissance data, photos, star maps, and the coordinates of the Forerunner Artifact, which was now on Earth. However, the Covenant had not identified Earth as the Human homeworld, and the ''[[Unyielding Hierophant]]'s'' fleet was never expressly identified to be intending to assault Earth; this is merely a reasonable assumption made by the Human forces upon discovery of the fleet's destination of [[Sol]]. 

This leaves the exact nature of the fleet's mission uncertain, as there is no definitive proof that the Covenant were intending to attack the Human homeworld. The surviving Humans, however, believed this fleet to be a direct threat to Earth, and, using a captured Covenant [[flagship]], lured the fleet into a trap and destroyed it.

A few weeks after this defeat, the [[Prophet of Regret]] led a small Fleet of fifteen ships to Earth, supposedly in order to locate a Forerunner artifact known as the "[[The Ark|Ark]]". Though hopelessly outgunned by the UNSC's new orbital defense grid of MAC guns, the Prophet of Regret's flagship managed 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 counter-attack by the [[Marines]] and John-117 drove them back. With his fleet destroyed in orbit when he landed, Regret was forced to retreat. His carrier jumped into Slipspace from within the city, damaging it severely.

Unfortunately for Regret, four Human ships, the ''[[UNSC In Amber Clad|In Amber Clad]]'' among them, had followed them through their own Slipspace rupture to [[Installation 05|Delta Halo]]. With the orders "Find out why he came to Earth; why he came here," the Master Chief was hard-dropped 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. However, they were withdrawn by the Prophet of Truth as part of the plan to remove the Sangheili from power in the Covenant. The Chief killed Regret. The Prophet of Truth then gave the order to glass the temple in which Regret was residing. It seemed as though Master Chief was eliminated. In fact the Chief narrowly avoided being glassed, only to be captured by the [[Gravemind]].

[[File:War.jpg|thumb|right|250px|The Great Schism begins.]]

Meanwhile, the majority of the Human forces on ''In Amber Clad'' had traveled to Delta Halo's [[Library]] to obtain the [[Index]], which is the key to firing Halo. Originally, the Covenant had been unaware of the Index's importance, but luckily for them, Arbiter Thel 'Vadamee had obtained [[343 Guilty Spark (Monitor)|343 Guilty Spark]], the monitor of [[Installation 04]], while destroying the Heretic base. The monitor, known to the Covenant as an Oracle, told the Prophets of the Index and the Arbiter was sent to retrieve the "Sacred Icon". The mission was complicated though by the unexpected release of the Flood. Despite this, the Arbiter successfully reached the Library and prevented the Humans from claiming the Index. Just as [[Miranda Keyes]] claimed the index, the Arbiter stole it from her, kidnapping her and [[Sgt. Johnson]]. However, then Index was stolen from the Arbiter by the [[Brute Chieftain]] [[Tartarus]], who was under the Prophets' orders to retrieve the Index and kill the Arbiter, whom Tartarus knocked down an apparently bottomless shaft. With the Index secure, the Prophets then ordered the [[Jiralhanae]] to begin eradicating the [[Sangheili]], thus starting the [[Covenant Civil War]]. Ultimately this led to the death of [[Tartarus]] at the hands of Vadamee and Johnson and an alliance between the Separatists and the Human forces. Delta Halo was prevented from firing by Miranda Keyes and the Flood killed the [[Prophet of Mercy]], leaving the Prophet of Truth firmly in control over the Covenant.

===The Battle of Onyx===
[[File:Ghosts of Onyx Cover.jpg|thumb|250px|right|[[SPARTAN Program|SPARTANs]] at the [[Battle of Onyx]].]]

Long before the events around Halo, the classified UNSC colony of [[Onyx]] had been designated the headquarters and training ground for the SPARTAN-III Program. However, the UNSC had no idea that the planet was in fact a huge [[Forerunner]] construct, integral to the [[Halo Array]], and containing trillions of [[Onyx Sentinel|Sentinels]]. After John-117's destruction of Alpha Halo, the Sentinels were roused by the disruption of the Halo network and the portal leading into the [[Shield World]] at the planet's core began to close. At this time, a small group of SPARTAN-IIIs were training in a top honors exercise on the surface. After the humans failed to exchange the proper counter-responses, the Sentinels relabeled the "[[Reclaimer]]s" as aboriginal subspecies and began to exterminate them. Led by [[Kurt-051]], the SPARTAN-IIIs fought a guerrilla war against the Sentinels until Doctor [[Catherine Halsey]] arrived on Onyx and explained the wider situation. Knowing that the Forerunner technology buried in Onyx's core could turn the tide of the war for humanity, Halsey used Forerunner technology to send a message to [[Fleet Admiral]] [[Terrence Hood|Sir Terrence Hood]], requesting reinforcements. Hood deployed [[Blue Team]] to Onyx, who stole a [[Covenant Destroyer]] to reach the planet in time.

Meanwhile, the [[Covenant Separatists]] under the leadership of [[Imperial Admiral]] [[Xytan 'Jar Wattinree]] had deployed a fleet to Onyx to claim the "sacred relics" for their fight against the Jiralhanae and the other [[Covenant Loyalists|Loyalists]]. After Blue Team made landfall, [[Fleet Master]] [[Voro Nar 'Mantakree]]'s fleet arrived at Onyx, taking down hundreds of orbiting Sentinels before discovering the UNSC forces in the recently-uncovered Forerunner city below. 'Mantakree personally led the Covenant forces on the surface, before the UNSC [[Battlegroup Stalingrad]] arrived and used tactical skill and indirect help from the Sentinels to destroy the majority of the Separatist fleet before being wiped out by reinforcements from [[Joyous Exultation]], with only [[UNSC Dusk|one ship]] escaping.

On the surface, the Spartans had discovered the [[Core Room Antechamber]] and were preparing to enter the Shield World. They managed to hold off hundreds of Covenant troops before being forced to retreat into the Core, while Kurt-051 sacrificed himself by detonating two [[FENRIS Nuclear Warhead]]s, killing the entire Separatist force. Following the Core being sealed, Onyx broke up into trillions of Sentinels, guarding the construct.

===Arrival of the Flood and Sangheili/Human Victory (2552-2553)===
[[File:Humans_&_Sangheili_Shadow_of_Intent.jpg|thumb|left|The Sangheili and Humans make ready to finish Truth and the Covenant at [[Installation 00]].]] 
[[File:H3 E3 Orbital Battle.jpg|thumb|right|250px|The battle between Covenant Separatists & Loyalists, raging over Installation 00.]]
{{Quote|In memory of those fallen in the defense of Earth and her Colonies. March 3, 2553.|[[Hillside Memorial]]}}

Following the Flood infestation of ''High Charity'', 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 a SPARTAN-II had stowed away with him on board his ''Dreadnought''. By the time Truth arrived at Earth, a full-scale battle in space and on the ground was underway between UNSC and [[Covenant Fleet]]s.

After much fighting, the Human forces on Earth on the naval side had taken heavy casualties. However, the Covenant fleet was also vastly reduced and focused on securing an enormous unearthed Forerunner structure near the ruins of New Mombasa. With the arrival of John-117, the remaining UNSC forces launched an assault on the area, sweeping aside all Covenant resistance and finally launching an all-out attack on the Prophet of Truth's [[Forerunner ship]].

However, Truth quickly activated a large [[The Artifact|portal]] and escaped. Events were further complicated by an unexpected attack by the Flood. Thanks to the timely arrival of the Sangheili, the Flood force was vanquished but not before Master Chief recovered a recording from Cortana, who had stayed behind on ''High Charity''. Cortana's message told of a means to stop the Flood on the other end of the portal. A small fleet of Human and Sangheili forces was sent through the portal, leading them to the Ark, just outside the [[Milky Way Galaxy]]. The Covenant fleet above the Ark immediately attacked. Though the joint Human-Sangheili fleet was outnumbered 3-1, the battle ended in defeat for the Covenant Loyalist Fleet. Simultaneous to the the space battle between Jiralhanae and Sangheili ships, UNSC forces were deployed to the surface of the Ark.

The final battle of the war was fought in December [[2552]] as Truth attempted to activate the [[Halo rings]]. Led by the Master Chief, the Human forces smashed through the remaining Covenant resistance on the ground. The battle was complicated by the arrival of ''High Charity''. As the Flood began to spread, the Chief and the [[Thel 'Vadamee|Arbiter]] went on to thwart Truth, who died in mid-Flood-infection at the Arbiter's hand with the Flood helping to reach him.  John-117 deactivated the Halo Array and brought an end to that threat as well. With the Covenant forces completely shattered, Truth's death marked the effective end to the war.  The Flood still remained a threat, but were destroyed by John-117, the Arbiter, Cortana and Sergeant Johnson by firing the Halo over the Ark, destroying both, but John-117 was presumed dead afterward as he never made it back to Earth.

[[File:Attend2.PNG|thumb|right|200px|The ceremony held to honor the fallen.]]

Some months later, in March 3 of [[2553]], a [[Hillside Memorial|monument was erected on a hillside]] near the Portal to the Ark to commemorate the billions of men and women killed during the war, and [[John-117|Spartan-117]]'s name was included as he was presumed MIA by the UNSC, as no Spartan could be declared dead. Lord Hood shook hands with the Arbiter to signify an end to hostilities. Both sides then started rebuilding all the damage the war had cost.

{{clear}}

==Factions==
===United Nations Space Command===
[[File:Perfect Black UNSC logo.png|thumb|right|The emblem of the [[United Nations Space Command|UNSC]].]]
'''Leaders:''' [[UNSC High Command|HIGHCOM]]

'''Homeworld:''' [[Earth]]

'''Military Forces:''' Unknown, likely in the hundreds of millions or billions.<ref name=HE:PH></ref>

===Covenant===
'''Leaders:''' [[Hierarchs]], [[High Council]]

'''Homeworld:''' Multiple worlds - different member races.

'''Capital City:''' ''[[High Charity]]''

'''Military Forces:''' Exact numbers are unknown, but are much larger than Humanity's forces.



===Covenant Loyalists===
'''Leader''': [[Prophet of Truth]]

'''Homeworld:''' Multiple worlds - different member races.

'''Military Forces:''' Exact numbers are unknown, but are assumed equal to or larger than the [[Covenant Separatists]]' forces.

===Covenant Separatists===
'''Leader''': [[Arbiter]] [[Thel 'Vadam]], [[Imperial Admiral]] [[Xytan 'Jar Wattinree]], [[Fleet Master]] [[Rtas 'Vadum]]

'''Homeworld:''' [[Sanghelios]], [[Balaho]], and [[Te]]

'''Military Forces:''' Exact numbers are unknown, but are assumed equal to or smaller than the [[Covenant Loyalists]]' forces.

===Flood===
'''Leaders:''' [[Gravemind]]

'''Homeworld:''' Unknown, extra-galactic.

'''Military Forces:''' Massive; probably in the trillions.

===Forerunner Constructs===
'''Leaders:''' Unknown, Forerunner [[Artificial Intelligence|artificial intelligence]] constructs including [[Monitor]]s such as [[343 Guilty Spark]].

'''Homeworld:''' Created on most constructs.

'''Military Forces:''' [[Sentinel]] count believed to be in the tens of trillions or possibly quadrillions,{{Citation needed}} as there are multiple [[Shield World]]s and [[Onyx]] alone was composed of trillions of Sentinels.

==Timeline==
===2524 ''(Pre-War)''===
*A damaged human civilian freighter, ''[[Horn of Plenty]]'', suffers a Slipspace drive malfunction from Harvest to Madrigal, forcing the unmanned freighter to exit back into normal space. A Covenant vessel, ''[[Minor Transgression]]'', comes into contact after hours of the freighter's isolation. The Covenant vessel targets the freighter, and a Jackal boarding crew enter.

===2525===
*The [[Skirmish Over Harvest|first battle]] between Humanity and the Covenant takes place prior to the outbreak of the war. Humanity attempts to gain a truce between the races through a pictogram of trade and peace between the Covenant and Humanity, but to no avail. ''(Pre-War)''

*The Covenant launch a full-scale [[First Battle of Harvest|assault]] on Harvest, glassing the planet. Afterward, the Minister of Fortitude becomes the [[Prophet of Truth]] and declares war on Humanity.

*Shortly after the attack on Harvest, the colonies of [[Green Hills]] and [[Second Base]] are glassed.

*The [[Battle of Chi Ceti]] takes place.

===2526===
*[[Second Battle of Harvest]]. The UNSC and Covenant meet in ship-to-ship combat for the first time; the Covenant are outnumbered and out gunned, nevertheless the battle is a high priced victory for the [[UNSCDF]], costing the UNSC 13 ships or about one third of the fleet which was assembled to encounter the threat. The Covenant would return to Harvest later in the year, and the battle for the planet, dubbed by the UNSC as the [[Harvest Campaign]], would last for the next five years.
*[[Battle of Alpha Aurigae]]. Another ship-to-ship battle, where the UNSC outnumber the Covenant almost 10-1, but lost a third of the ships. This was one of the rare naval "victories" for the UNSC

===2528===
*[[Battle of XI Boötis A]], the UNSC fleet of 70 warships destroy 8 enemy vessels, losing 30 of their own in the process
*[[Madrigal]] is glassed by The Covenant

===2528 or 2529===
*[[Battle of Hat Yai]].

===2530===
*The Covenant [[Battle of Eridanus II|destroys]] the UNSC colony world of [[Eridanus II]]
*[[Battle of Groombridge-1830]], 11 UNSC Destroyers are lost in attempt to defeat a Covenant fleet of 3 warships

===2531===
*The UNSC finally manages to [[Harvest Campaign#Final Liberation of Harvest|retake Harvest]], ending the five-year long Harvest Campaign in a UNSC victory.
*[[First Battle of Arcadia]]
*[[Battle of the Flood-controlled Shield World]]
*[[Kurt-051]] is kidnapped by Section III of ONI to train the classified [[SPARTAN-III]]s, in a need for more supersoldiers to fight the Covenant.

===2535===
*The Covenant [[Glassing|destroys]] the UNSC colony world of [[Jericho VII]] in the [[Battle of Jericho VII]]. 
*[[Battle of the Unnamed Star System]]
*[[Battle of Charybdis IX]]
*[[Battle of the Rubble]]
*In the course of four short years, UNSC forces have been hammered, despite excellent leadership and tactical brilliance. It is simply a matter of being outgunned; Covenant kill ratios tend to top three to one in ship-to-ship combat. By 2535, virtually all of the [[Outer Colonies|Outer Colony]] worlds have been glassed by the Covenant.

===2536===
*Covenant forces begin to swarm into the [[Inner Colonies]]. For several years the war falls into a pattern: humans win isolated battles, typically during ground operations, but at a horrible cost. In space combat, the humans are losing at a precipitous rate, and one by one, the colonies fall.

===2537===
*Discovery of Covenant Manufacturing Plant [[K7-49]] at the [[Battle of New Harmony]].
*[[Battle of New Constantinople]], Covenant [[glassing]] of [[New Constantinople]].
*[[Battle of Leonis Minoris]], Covenant destruction of [[Leonis Minoris]].
*[[Siege of the Atlas Moons]] was a rare victory for the [[UNSC]], as victories in space-based fighting were uncommon for the UNSC Fleet.
*[[Operation: PROMETHEUS]]: UNSC Victory. [[SPARTAN-III]] [[Alpha Company]] is killed by Covenant forces.

===2539===
*[[Battle of Kholo]], Covenant forces glass the colony of [[Kholo]].

===2543===
*On March 6 the [[Battle of 18 Scorpii]] takes place. In the battle prior-unknown Independent/Insurrectionist human forces assist three UNSC destroyers in defeating a Covenant CPV destroyer.
*[[Cole|Vice Admiral Preston J. Cole]] is presumed to have made [[Admiral Cole's Last Stand|his last stand]] at the [[Battle of Psi Serpentis]] on April 18.  Over 300 Covenant ships destroyed in the battle.

===2545===
*[[Operation: TORPEDO]]: UNSC Victory. All participating SPARTAN IIIs, with the exception of Tom-B292 and Lucy-B091 of [[SPARTAN-III]] [[Beta Company]] are killed by Covenant forces.

===2547===
*The UNSC colony of [[Skopje]] is [[Battle of Skopje|destroyed]] by the Covenant.

===2549===
*[[Siege of Paris IV]], Covenant victory.
*[[Second Battle of Arcadia]], Covenant victory, Arcadia is glassed.<ref>[[Halo Waypoint]] article on Arcadia</ref>

===2552===
====July====
*[[Battle of Draco III]]. Covenant kill all UNSC ground forces and captured thousands of civilians. Later a [[SPARTAN-II|SPARTAN]] squad arrive and kill all Covenant forces only to find that the civilians were killed by ravenous, raging Grunts and Jackals.

*[[Battle of Sigma Octanus IV]]. The single greatest UNSC victory since [[Harvest]]. However, the Covenant gain what they seek: the location of [[Installation 04]]. They also discover the Human presence on [[Reach]].

====August====
*[[Fall of Reach]]. 750 Covenant ships destroy over 130 UNSC ships and 20 [[ODP]]s for the loss of at least two-thirds of their fleet. It is a major Covenant victory: Reach is the last major stronghold before [[Sol]]. The ''[[UNSC Pillar of Autumn]]'' escapes.
*[[Battle of Tribute]]. Along with other colonies in the [[Epsilon Eridani System]], [[Tribute]] is invaded by Covenant forces. The colony is not glassed instantly, but remains under siege by Covenant forces for some time.

====September====
[[File:Ddd03.jpg|thumb|right|Part of the wreckage of the destroyed [[Installation 04]].|200px]]
*[[Battle of Verge]]. A Covenant [[Beacon]] transmitting [[Helium|helium-3]] for ships blockading Tribute is destroyed by [[Team Black]].

*[[Battle of Line Installation 1-4]]. A UNSC ship on a covert mission, as well as a Covenant Assault Carrier, crash on a remote moon with a [[Line Installation 1-4|Forerunner relic]]. In the ensuing engagement, the surviving UNSC forces side with the Covenant against the installation's defense systems.

*[[Battle of New Jerusalem]]. Following an attack on the UNSC colony of [[New Jerusalem]], the [[26th Marine Expeditionary Force]] is sent to reinforce the UNSC forces already present. The colony is eventually lost to the Covenant and the survivors fall back to Earth.

*[[Battle of Installation 04]]. The ''Pillar of Autumn'' engages the Covenant, [[Halo]] expedition. After four days the battle degenerated into a four-way melee as the Flood organisms are released and Forerunner constructs, Sentinels seek to contain the outbreak. The crew of the ''Pillar of Autumn'' are instrumental in preventing the Flood from escaping and the installation from firing by destroying the installation. There are only a handful of survivors.

*[[Skirmish over Threshold]]. UNSC survivors from the Battle of Installation 04 rally in orbit over [[Threshold]].  Using their limited resources to the fullest they manage to capture the Covenant vessel ''[[Ascendant Justice]]'' and use it to escape.

*[[Raid of Reach]]. John-117 and some of the survivors of the Battle of Installation 04 raid Reach to rescue a [[SPARTAN]]-II team trapped on Reach by a Covenant fleet. They rescue the Spartan squad leaving a great deal of damage to the Covenant fleet ships and the ground forces.

*[[Operation: FIRST STRIKE]]. Six [[SPARTAN-II]] super soldiers route and destroy a fleet of 500 Covenant warships preparing to jump to Earth. This is the single greatest victory, for the humans during the entire war and the single greatest loss to the Covenant.

====October====
*[[Battle of Earth]]. 15 Covenant ships assault Earth, defended by the [[UNSC Home Fleet]] and 300 ODPs. The Covenant were not expecting the heavy human presence, as well as their new orbital MAC defenses, and are completely destroyed save for the Prophet of Regret's [[Regret's Carrier|Assault Carrier]] and the [[Pious Inquisitor]]. However, a fleet of Covenant capital ships appears soon after, prolonging the battle.

====November====
*[[Battle of Installation 05]]. Regret's Assault Carrier from the initial invasion of Earth retreats to [[Installation 05]], pursued by four small UNSC warships. Only one, the [[UNSC In Amber Clad|UNSC ''In Amber Clad'']], arrives in time to participate in the battle.
*The [[Prophet of Regret]] is assassinated by John-117.
*The [[Civil War of the Covenant]] begins. Covenant forces are thoroughly divided between the Elites and the Brutes. Every race in the Covenant takes sides.
*The [[Prophet of Mercy]] is later killed by a Flood Infection Form.
*Again, the installation is prevented from firing and the Flood appear to take control of the installation and High Charity.

*[[Battle of Onyx]]. The destruction of [[Installation 04]] wakes dormant Forerunner installations, including the Sentinels on Onyx which then threaten the UNSC base there. The SPARTAN-IIs of Blue Team fight their way off of [[Earth]] and commandeer a [[Covenant Destroyer]], the ''[[Bloodied Spirit]]'', to relieve [[Onyx]]. Covenant and UNSC ships converge on Onyx but ultimately all are destroyed except for the [[UNSC Dusk|UNSC ''Dusk'']]. UNSC survivors retreat within the Onyx [[Shield World]].

*The Battle of Earth continues. The Covenant Loyalists led by the Prophet of Truth arrive at Earth in force, to reinforce the Covenant forces already present. During the following week, [[UNSC Marine Corps|Marines]], with help of the [[Covenant Separatists|Separatists]], pushed back the Loyalist invaders.

===Late 2552===
*[[Battle of Installation 00]].
*All Loyalist vessels are destroyed over the Ark by the Separatist Fleet.
*The final Covenant religious leader, the [[Prophet of Truth]], is executed by the Arbiter with help from the Flood. The Master Chief stops the Ark from firing the Halo Rings.
*''High Charity'' is destroyed by the Master Chief after he blasts the city's main reactors causing them to go critical.
*The Battle of [[Installation 04 (II)]]. Thel 'Vadam, John-117 and Johnson battle to the control room that's on [[Installation 04 (II)]]. Guilty Spark runs rampant, killing Johnson before being destroyed. [[Installation 04B]]’s Sentinels turned on John-117 and Thel 'Vadam. The unfinished Installation 04 is activated, damaging the Ark and destroying the entire Flood infestation including the [[Gravemind]]. These final events ended The Human-Covenant War. However, the ''Dawn'' is torn in half while entering the portal home, sending 'Vadam to Earth, but leaving John and Cortana lost in space.

===December===
*The Arbiter returns to Earth in the frontal half of ''Forward Unto Dawn'', crashing into the ocean. He is safely cut out of the wreckage by UNSC forces. 

===2553 ''(Post War)''===
====March====
*While the fighting finished in December, hostilities were not ceased officially until March, with the UNSC and their allies emerging victorious. The victors erect a [[Hillside Memorial|monument]] on a hillside near the Ark's Gateway to commemorate those fallen. Despite being listed MIA as per protocol, the UNSC widely believe John-117 to be dead. The [[Sangheili]] then depart for the return to [[Sanghelios]].

==Trivia==
*The very first Covenant species to encounter humanity were the [[Unggoy]], the [[Huragok]], the [[Kig-yar]], and the [[Jiralhanae]], - in that order - all prior to the inception of the war.
*Avery Johnson was the only human to witness both the beginning and end of the Human-Covenant War, as he was present when [[Harvest]] was attacked and saw Truth killed, which signified the end of the war.

==Sources==
<references/>

{{Human-Covenant War}}
{{Humanwars}}
{{Covenantwars}}

[[de:Allianz - Menschen Krieg]]
[[Category:Human-Covenant War]]