Editing Human-Covenant War

{{Status|Canon}}

|prev=[[Insurrection]] {{c|original conflict}}

|conc=*[[Insurrection#During the Human-Covenant War|Insurrection]] {{c|in reduced capacity}}

*[[Great Schism]]

**[[Insurrection#Post-war resurgence|Insurrection]] {{c|postwar resurgence}}

|image=[[File:Other Wiki HCW collage.png|415px]]<br>Clockwise from top left: [[Insurrectionist]]s are attacked by the Covenant at [[Alpha Corvi II]]; UNSC forces under fire inside a [[Relic (location)|Relic]] on [[Harvest]]; a {{Class|CAS|assault carrier}} [[glassing]] [[Kholo]]; [[John-117]] on a [[Pelican]] over [[Installation 04]]; [[Sangheili Honor Guardsman|Sangheili Honor Guardsmen]] fighting [[Jiralhanae]] at the start of the [[Great Schism]]; [[Arbiter]] [[Thel 'Vadam]], John-117, Sergeant [[Avery Johnson]], and [[343 Guilty Spark]] on [[Installation 08]]

|date=*[[2525|February 11, 2525]]<ref>[[First Battle of Harvest]]</ref>–[[2552#December|December 11, 2552]]<ref>[[Halo 3]]</ref> {{C|[[2553#March|March 3, 2553]] ([[Voi Memorial|official ceremony]])}}

|result='''Human-Sangheili victory'''<ref>''[[Believe]]'', [[Museum]]</ref>  

*Covenant Empire collapses{{Ref/Level|Id=The Covenant|H3|[[The Covenant (level)|The Covenant]]}}

*[[Flood]] threats sterilized and contained{{Ref/Reuse|The Covenant}}

*Human and [[Fleet of Retribution|many]] Sangheili forces [[Treaty of 2552|reconcile]]{{Ref/Level|Id=Halo|H3|[[Halo (Halo 3 level)|Halo]]}}<ref>''Halo: Glasslands'', p. 60</ref>

|side1=*{{Icon|UEG}} '''[[UEG]]'''

**{{Icon|UNSC HCW}} '''[[United Nations Space Command|UNSC]]'''

*{{Icon|Covenant FB}} '''[[Covenant separatists]]''' {{C|From [[2552#November|November 3, 2552]] onwards}}

*{{Icon|Insurrectionist}} '''[[Insurrectionists]]'''

**'''[[United Rebel Front|URF]]'''

|side2=*{{Icon|Covenant FB}} '''[[Covenant]]'''

|side4=*{{Icon|Forerunner}} '''[[Sentinel|Forerunner constructs]]'''<ref group="notes">'''Allied''' with UNSC/Fleet of Retribution '''only''' during the 1st half of the Battle of Installation 04 (UNSC only), Battle of Installation 05 and Battle of the Ark. Elsewhere and excluding these battles, Forerunner constructs were '''hostile''' to the UNSC/Fleet of Retribution' (including during the 2nd half of the Battle of installation 04 (UNSC only), Battle of the Etran Harborage (UNSC only), Battle of Onyx (UNSC only) and the Raid on Installation 08). However, Forerunner constructs were '''hostile''' to both Flood and Covenant forces throughout the entire war.</ref>

*[[Admiral|ADM]] [[Margaret Parangosky]]

*[[Shipmaster]] / [[Fleetmaster]] [[Rtas 'Vadum]]

*[[Special Operations Commander]] [[Rtas 'Vadum]]ee {{c|pre-Great Schism}}

*[[Arbiter]] [[Ripa 'Moramee]]†

*[[Fleetmaster]] [[Voro Nar 'Mantakree]]† {{c|pre-Great Schism}}

*[[Imperial Admiral]] [[Xytan 'Jar Wattinree]]† {{c|pre-Great Schism}}

*[[Supreme Commander]] [[Thel 'Vadam]]ee {{c|pre-Great Schism}}

*Approximately 23 billion civilian and military casualties by October 20, 2552;<ref name=HE:PH>'''[[Halo: Evolutions - Essential Tales of the Halo Universe|Halo: Evolutions]]''', "[[Palace Hotel]]", ''page 351''</ref> billions more during the [[Battle for Earth]]<ref>'''Halo: Glasslands'''. ''page 151''</ref>

;Heavy Sangheili casualties

The '''Human-Covenant War''',<ref>'''Halo: The Fall of Reach (2001)''', ''back cover description''</ref><ref>'''Halo: The Flood (2001)''', ''back cover description''</ref> also known as the '''Covenant War''',<ref>'''[[Halo: The Essential Visual Guide]]''', ''pages 19, 74, 75, 92, 95, 98, 105, 112, 113, 120''</ref><ref>'''Halo Waypoint''': [http://halo.xbox.com/en-us/intel/featured/video/headhunters-1/c3d2dcb3-ac3d-4771-a270-e55e33ae118b ''Headhunters'' Part 1], [http://halo.xbox.com/en-us/intel/featured/video/herocourage/c2ada678-e9ce-4db9-9ce9-1864070bd198 ''Hero - Courage'']</ref><ref name="title" group="notes">The name "Covenant War" is most often used by media from [[343 Industries]]. However, the less common "Human-Covenant War" is more descriptive and is therefore used by ''Halopedia''.</ref> the '''Great War''',<ref>''Halo: First Strike'' (2010), [[Petra]]</ref> and the '''War of Annihilation''' by the [[Covenant]],{{Ref/Novel|SoR|Chapter=3}}{{Ref/Novel|DW|Chapter=1}}{{Ref/Book|Enc22|Page=193}}{{Ref/Site|URL=https://www.halowaypoint.com/news/the-new-halo-encyclopedia-is-out-today|Site=Halo Waypoint|Page=The New Halo Encyclopedia is Out Today|D=11|M=03|Y=2023}} was a major interstellar conflict pitting [[humanity]] and its [[United Nations Space Command]] against the Covenant during the mid-26th century between [[2525#February|February 11, 2525]] and [[2552#December|December 11, 2552]]. There were two additional factions sporadically involved in the conflict: the [[Flood]] and a small number of surviving [[Sentinel|Forerunner constructs]]. Both factions proved to be invaluable to the efforts of humanity, as the information taken from Forerunner constructs and the Flood invasion of ''[[High Charity]]'' were helpful in [[Great Schism|splitting the Covenant apart]] in November 2552.

After the [[Treaty of 2552|ceasefire]] was declared, the Great Schism continued in the form of [[Sangheili-Jiralhanae war|wars]] between the Sangheili and the Jiralhanae until at least [[2559]].<ref>'''Halo: Evolutions''', ''The Return''</ref> Concurrent to this, the Sangheili species fell into [[Blooding Years|civil war]], as did the Jiralhanae, while the UNSC itself had to deal with a resurgence in the [[Insurrection]]. In the wake of the Covenant's cessation, its former member species fragmented and formed many new [[Covenant remnants|splinter factions]]. Among the most notable of these smaller groups was the religiously devout [[Jul 'Mdama's Covenant faction|new “Covenant”]] formed in the disarray following the war by [[Shipmaster]] [[Jul 'Mdama]]. The UNSC occasionally engaged in [[Post-Covenant War conflicts|smaller conflicts]] with Jul's faction and a few others, until late [[2558]].<ref name="Spops">[[Halo 4]] [[Spartan Ops]], level [[Departure]]</ref>

==Background==

In [[2492]], the Covenant would make their last major species incorporation, the [[Jiralhanae]], following the discovery of their homeworld of [[Doisac]].{{Ref/Book|Id=EncC4|Enc|Section=Chapter Four: The Covenant - The History of the Covenant|Page=115 (2009 edition), 121 (2011 edition)}}

==War==

Realizing the threat posed to humanity by the Covenant, the UNSC [[Colonial Military Authority]] gave [[Vice Admiral]] [[Preston Cole]] the command of the then-largest fleet in human history with orders to [[Second Battle of Harvest|retake Harvest]],<ref name="Genesis">'''[[Halo Wars: Genesis]]''', pages 1-10</ref> which occurred in [[2526]].<ref>'''Halo: Evolutions''', ''The Impossible Life and the Possible Death of Preston J. Cole'', pages 462-467</ref> He would then spend 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]].{{Ref/Reuse|Genesis}}<ref name="battles">'''Halo: Evolutions''', ''The Impossible Life and the Possible Death of Preston J. Cole'', page 470</ref> 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.<ref>'''[[Halo: The Essential Visual Guide]]''', ''page 188''</ref> Because of the threat the Covenant posed, the UNSC began deploying the [[SPARTAN-II Program|SPARTAN-II]]s on November 2nd, 2525,{{Ref/Novel|Id=hsschapter2|HSS|Chapter=2}} super soldiers originally trained to fight the [[Insurrection]]. The Spartans became one of humanity's greatest — and most celebrated — defenders, demonstrating a remarkable ability to turn the tide of battle. Their prowess was not lost on the Covenant, who came to fear the Spartans as "[[demon]]s".<ref>'''[[Halo: The Fall of Reach]]''', ''page 103''</ref>

From that point on, the Covenant continued to attack and destroy the humans wherever 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, fighting a war of extermination, did not need to commit to full ground invasions except in special circumstances; their ships simply needed to destroy space-borne defenses and any other threats around the planet. They would then reduce the planet's surface to glass with orbital plasma bombardment.<ref>''[[Halo Encyclopedia (2009 edition)]]'', Chapter 1, p. 33</ref> In general, human missiles and magnetic acceleration weapons were asymmetrically matched with Covenant energy shields and plasma weaponry. The few major victories achieved by the UNSC were usually due to tactical genius, extensive use of nuclear weapons, the rapid deployment of Spartan teams, or decisive ground engagements where UNSC technology and skill outmatched Covenant tactics. At the outset of the war, the UNSC employed a [[Wikipedia:defence in depth|defence in depth]] tactical doctrine, making extensive use of [[M5 Talos|automated turrets]] to delay Covenant forces.<ref name="PL Turret">''Halo Wars 2'', [[Phoenix Logs]] - Turret</ref> They were eventually forced to abandon this doctrine as the war continued to grind down human armies and industrial centres,{{Ref/Reuse|PL Turret}} learning the dangers of relying on fixed installations when employed against enemies with orbital fire support.<ref name="PL Siege">''Halo Wars 2'', [[Phoenix Logs]] - Siege Turret</ref> The UNSC began to develop a modular [[firebase]] system (based on pre-existing [[colony starter unit]]s used for colonization of planets<ref>[http://www.halowars.com/GameInfo/UNSC.aspx ''Official Halo Wars Community Site'': UNSC] (defunct, [[Archive:Halowars.com/UNSC|Archived]])</ref>) in response to pinpoint Covenant targeting of large military command and control installations with orbital strikes, and the inability of standard counter battery systems to detect, deflect, or defeat plasma-based artillery bombardment.<ref name="PL Siege"/>

[[File:ApexBattleImage.png|thumb|200px|The {{UNSCShip|Spirit of Fire}} engages the {{Pattern|Sinaris|heavy destroyer}} ''[[Proclamation's Tithe]]'' in [[Trove]].]]

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]], [[Bliss]], [[Madrigal]], [[Asmara]] and [[Biko]].

In [[2531#February|February 2531]], [[Arbiter]] [[Ripa 'Moramee]], under the command of the [[Prophet of Regret]], began leading searches for [[Forerunner]] technology to aid in the Covenant war effort during the end of the [[Harvest campaign]]{{Ref/Level|HW|[[Alpha Base (Halo Wars level)|Alpha Base]]}} and the [[Battle for Arcadia]]. With the Covenant having discovered the Forerunner [[shield world]] [[Trove]] sometime prior, the Prophet of Regret intended to use a fleet of {{Class|Sojourner|dreadnought}}s docked at the [[Apex Site]] to crush humanity "quickly and with ease."{{Ref/Level|Id=HWscarab|HW|[[Scarab (Level)|Scarab]]}} With Ripa having kidnapped Professor [[Ellen Anders]] at [[Arcadia]] to use as a [[Reclaimer]] to activate the shield world, he was pursued by the {{UNSCShip|Spirit of Fire}}, leading to [[Battle of the Trove|a battle]] at the Etran Harborage. In the battle, Ripa was killed by Sergeant [[John Forge]] who subsequently sacrificed himself to destroy the Etran Harborage by causing its internal sun to go [[supernova]]. The Covenant plan was foiled, but the ''Spirit of Fire'' sacrificed its [[slipspace drive]] to cause the supernova, leaving the ship and its crew stranded in deep space.{{Ref/Level|HW|[[Escape (Halo Wars level)|Escape]]}}

The UNSC's sole hope apparently lay with the SPARTAN-II Program. However, there were never enough Spartans to decisively 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.<ref>''Halo: Ghosts of Onyx'', p. 43-46</ref>

After just six years of combat, space battles with the Covenant had depleted the UNSC's nuclear stockpile to almost nothing in at least one sector of space.{{Ref/Novel|GoO|Chapter=1}}

 

With the majority of the Outer Colonies glassed or abandoned, the UNSC faced an economic crisis, as many of their [[agriculture world]]s had been destroyed, leading to food shortages. On [[Charybdis IX]], food riots were common.<ref>''Halo: The Cole Protocol'', p. 106</ref> Meanwhile, Covenant forces began to encroach on the [[Inner Colonies]].<ref>''Halo: The Cole Protocol'', p. 25</ref> In response, the UNSC issued [[United Nations Space Command Emergency Priority Order 098831A-1]], otherwise known as 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.{{Ref/Reuse|Genesis}} [[Insurrectionist]] attacks increased in the face of what the colonies perceived as a removal of their right to freedom of movement. This was to culminate in the discovery of Insurrectionists using Covenant weapons supplied by apparently renegade [[Kig-Yar]]. Shocked, the UNSC viewed this as a major threat to security.<ref>''Halo: The Cole Protocol'', p, 109</ref> Upon learning of this, the [[Prophet of Regret]] declared such weapons as heresy, and as a result dispatched [[Thel 'Vadam]]ee to destroy the source of the modified weapons: a remote asteroid habitat known as [[the Rubble]].<ref>''Halo: The Cole Protocol'', p. 146</ref>

===Inner Colony push (2536-2551)===

[[File:Origins ii Human-CovenantWar.jpg|thumb|225px|Humanity, heavily out-gunned, lost much ground to the Covenant.]]

For fifteen years, the war ground on in a predictable pattern; costly and rare victories on the ground for UNSC forces, with near total Covenant space superiority.{{Ref/Book|Enc11|Page=205}} 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]],<ref>''Halo: Ghosts of Onyx'', p. 341</ref> 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.<ref>''[[Halo: First Strike]]'', p. 179 ("John had never worked with the Admiral before, but his accomplishments during the battles for New Constantinople and the Siege of the Atlas Moons were well known.")</ref>

Of the few major wins in the 2540's for the UNSC, and one of the most significant and strategically advantageous was the [[Battle of Psi Serpentis]] in 2543. This engagement 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 supermassive gas giant. This detonation spurred spontaneous fusion at the core of Viperidae, temporarily turning the super gas giant into a brown dwarf star.<ref name="Psi Serpentis">''Halo: Evolutions'', "The Impossible Life and the Possible Death of Preston J. Cole", p. 476-482</ref> 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.{{Ref/Reuse|Alamo}}

While the Covenant had merely been slowed by the UNSC's military efforts, there was growing tension between the [[San'Shyuum]] and the [[Sangheili]] over the Human-Covenant War. At first, the Sangheili had followed the Prophets command to destroy the humans without question. But after more than twenty five years of war, humanity's continued and fierce resistance in the face of certain death had deeply impressed the martial Sangheili.<ref>''Halo: The Cole Protocol'', p. 139</ref> There was a growing consensus among the Sangheili that the humans had earned the right to be offered membership in the Covenant, which the Prophets continued to reject. At the same time, the [[Jiralhanae]], the one race which could challenge the Sangheili's dominance of the Covenant military, were rapidly earning favor with the Prophets, as they were less inclined to question orders.<ref>'''[[Conversations from the Universe]]'''</ref> In fact, even the Prophet of Clarity [[Zo Resken]] began to secretly question why humanity wasn't offered a place in the Covenant.{{Ref/Novel|BC|Chapter=15}}

=====The tide turns=====

[[File:H2A - Autumn.jpg|thumb|300px|The [[UNSC Pillar of Autumn|''Pillar of Autumn'']] pushes through the Covenant blockade and escapes [[Reach]].]]

The Covenant suffered a costly defeat on and around [[Installation 04]]. Here, the human survivors from the [[Halcyon-class light 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 their usual bombardment tactics.<ref>''[[Halo: The Flood]]'', p. 187</ref> The Covenant was soundly defeated in numerous raids led by SPARTAN [[John-117]], including an attack on a grounded cruiser, the ''[[Truth and Reconciliation]]'', successfully escaping with the captain of the ''Pillar of Autumn'', Captain Jacob Keyes.<ref>''[[Halo: Combat Evolved]]'', campaign level, [[The Truth and Reconciliation]]</ref> 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, instinctively spread quickly throughout the ring, killing or assimilating every unsuspecting human and Covenant in their path and would become a third party in the war.<ref>''Halo: Combat Evolved'', campaign level, [[343 Guilty Spark (level)|343 Guilty Spark]]</ref>

During the course of the battle, John 117 discovered the true nature of Halo and proceeded to detonate the crashed ''Pillar of Autumn's'' engines, destroying the ring, and escaped.<ref>'''Halo: Combat Evolved''', campaign level, ''[[The Maw]]''</ref> The destruction of the holy Halo 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 title of [[Arbiter]] and sent to quell a [[List of known Covenant heretics|heretic]] uprising that had taken root on the [[Threshold gas mine|Forerunner gas mine]] over [[Threshold]].<ref name="thearbiter">''[[Halo 2]]'', campaign level, [[The Arbiter]]</ref>

The Covenant discovered Earth as a result of an accident after the ''[[Seeker (AI)|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 [[Luna]], 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.<ref>'''i love bees'''</ref>{{verify}} This information was first relayed to the High Prophet of Truth, who, due to his personal socio-political machinations, kept it secret from his fellow Hierarchs.<ref name="tentwenty">'''[[Halo Waypoint]]''', [http://halo.xbox.com/en-us/Universe/Detail/ten-twenty/f4adbef8-e9bc-44f8-aefa-d8e9b69f7139 ''"Ten Twenty"'']</ref> Instead, he began to amass [[Truth's fleet|a massive fleet]] of approximately 500 ships to the command-and-control station ''[[Unyielding Hierophant]]''. The surviving humans from the battles of Installation 04 and Reach, however, discovered the fleet and the direct threat it posed to Earth. Using the captured Covenant [[flagship]] ''Ascendant Justice'', the small group of soldiers lured the fleet into a trap and destroyed it.<ref name="Alamo">'''Halo: First Strike''', ''pages 328-333''</ref>

A few weeks after this defeat, the [[Prophet of Regret]] discovered the location of a significant Forerunner artifact on his own. Without knowledge of the fact the planet housing this artifact was the human homeworld, Regret led a small fleet of fifteen ships to Earth, in order to locate [[Portal at Voi|a portal]] to an installation known as "[[Installation 00|the Ark]]".{{Ref/Reuse|tentwenty}} Though hopelessly outgunned by the UNSC's new orbital defense grid of MAC guns, the Prophet of Regret's [[Solemn Penance|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 resulted in their swift defeat. With his fleet burning in orbit, Regret was forced to retreat. His carrier jumped into slipspace from within the city, damaging it severely. Following Regret's jump, waves of Covenant reinforcement forces, including a [[Truth's fleet|support fleet]] sent by the Prophet of Truth, arrived, resulting in a month-long constant engagement on Earth.{{Ref/Generic|Id=lootcrate2|Heading=[[Halo Legendary Crate]]|Subheading=[[Halo Legendary Crate/Data Drops|Data Drop #2]]}}{{Ref/Novel|Id=goo204|Halo: Ghosts of Onyx|Page=204-205}}{{Ref/Reuse|tentwenty}}{{Ref/Site|Id=waypointvergil|URL=https://www.halowaypoint.com/en-us/news/canon-fodder-vergil-reality|Site=Halo Waypoint|Page=Canon Fodder - Vergil Reality|D=15|M=06|Y=2021}}

Unfortunately for Regret, four human ships including the ''[[UNSC In Amber Clad|In Amber Clad]]'', had followed them through their own slipspace rupture to [[Installation 05|Delta Halo]].<ref>''Halo 2'', campaign level, [[Delta Halo]]</ref> Led by John-117, the humans forced their way to the Prophet himself. At that moment, ''High Charity'', having learned of Delta Halo, arrived and launched multiple waves of [[Phantom]] dropships to aid Regret. These forces were withdrawn by the Prophet of Truth as part of his plan to remove the Sangheili from power in the Covenant. However, Truth ultimately underestimated the full impact his 'reforms' would have on the Covenant's chances for military victory. The Master Chief [[Assassination of the Prophet of Regret|assassinated]] Regret, dealing a heavy blow to the Covenant's political structure. John-117 narrowly survived only to be captured by the [[Gravemind]], who had already formed a plan to prevent the Covenant from completing their Great Journey.<ref>''Halo 2'', campaign level, [[Regret (Halo 2 level)|Regret]]</ref>

[[File:H2A Great Schism.png|thumb|300px|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. Covenant forces were dispatched to secure the index as well. However, the Index was stolen from the Arbiter by the [[Jiralhanae Chieftain]] [[Tartarus]], who was under the Prophets' orders to retrieve the Index and dispatch the Arbiter.<ref>''Halo 2'', campaign level, [[Quarantine Zone]]</ref> With the Index secure, the Prophets then ordered the Jiralhanae to begin eradicating the Sangheili, thus starting the [[Great Schism]]. Ultimately this led to the death of Tartarus at the hands of 'Vadamee and Johnson and a temporary alliance between the Sangheili and the human forces. Delta Halo was prevented from firing by Miranda Keyes while the Flood infected High Charity and absorbed the [[Prophet of Mercy]], leaving the Prophet of Truth firmly in control over the Covenant Empire.<ref>''Halo 2'', campaign level, [[The Great Journey (level)|The Great Journey]]</ref>

=====Onyx Conflict=====

[[File:Ghosts of Onyx Cover.jpg|thumb|250px|[[SPARTAN Program|SPARTANs]] during the [[Onyx Conflict]].]]

Meanwhile, the [[Joyous Exultation Covenant|Sangheili forces]] under the leadership of [[Imperial Admiral]] [[Xytan 'Jar Wattinree]] deployed a fleet to Onyx to claim the "sacred relics" for their fight against the Jiralhanae. Xytan would not live to hear of the results of this mission, as he and the majority of his fleet were annihilated by a UNSC [[NOVA bomb]] recovered from Reach.<ref>''Halo: Ghosts of Onyx'', p. 244-245</ref> 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 a [[Patterson's battle group|UNSC battlegroup]] arrived and used tactical skill and indirect help from the Sentinels to destroy the majority of the Sangheili fleet before being wiped out by reinforcements from [[Joyous Exultation]], with only [[UNSC Dusk|one ship]] escaping.<ref>''Halo: Ghosts of Onyx'', p. 333</ref>

=====Arrival of the Flood and Human-Sangheili victory=====

[[File:H3 LesserArkConflict.png|thumb|left|250px|The battle raging over [[Installation 00]].]]

The final battle of the war was fought on [[2552#December|December 11, 2552]].{{Ref/Reuse|fortitude}} A small fleet of human and Sangheili forces was sent through the portal, leading them to the Ark, just outside the [[Milky Way]]. As they arrived, the Covenant fleet above the Ark immediately attacked. Though the joint human-Sangheili fleet was outnumbered 3–1, the battle ended in defeat for Truth's Jiralhanae fleet. At the same time, UNSC forces were deployed to the surface of the Ark in order to stop Truth, who was attempting to activate the Halo Array from the Ark's [[Installation 00 Citadel|Citadel]].<ref>''Halo 3'', campaign level, [[The Ark (level)|The Ark]]</ref>

Led by the Master Chief, the UNSC 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, preserving all life within its firing pattern. With the Covenant forces completely shattered, Truth's death marked the effective end to the war.{{Ref/Reuse|The Covenant}} The Flood still remained a threat, but were eliminated by John-117, the Arbiter, Cortana and Sergeant Johnson by firing the isolated replacement Halo over the Ark itself, destroying [[Installation 08]] and damaging [[Installation 00]] severely. Although ''Forward Unto Dawn'' managed to reach the portal, the portal collapsed splitting the vessel in half. Trapped in the rear section of the frigate, John-117 placed himself into cryosleep until he could be retrieved, eventually drifting to the Forerunner shield world of [[Requiem]]. The UNSC's greatest soldier, and humanity's champion, was presumed dead.{{Ref/Reuse|Halo}}

=====The SUNSPEAR mistake=====

During the [[Battle for Earth]], Gray Team received a message stating Condition Endgame, meaning that the Covenant had appeared in the [[Sol system]] and the [[Cole Protocol]] had finally failed to protect the planet. Unable to reach [[Sanghelios]] as it was too well defended, Gray Team instead targeted [[Sangheili colonies|the colony world]] of [[Glyke]], home to billions of Sangheili. Though the war ended, Gray Team's ship had a damaged deep-space communications device and thus could not receive any orders to cease or withdraw. Confident that humanity was about to be destroyed, Gray Team took a vote and decided to carry out the mission, hoping that the slaughter would stop humanity's extinction. In December 2552, just days after [[Treaty of 2552|a tentative peace treaty]] was established with [[Thel 'Vadam]] and the [[Fleet of Retribution]], Gray Team destroyed Glyke with a [[NOVA bomb]]. With their ship damaged by the blast, Gray Team was forced to evacuate aboard [[Whiskey Tango Foxtrot One|their lifeboat]] and was left adrift in Glyke's remains, asleep in [[cryo chamber]]s.<ref>''[[Halo: Envoy]]'', p. 177-180</ref>

[[File:Attend2.PNG|thumb|250px|The ceremony held to honor the fallen.]]

After the war, [[Codename: SURGEON]] authored [[Eleventh Hour reports|a series of reports]] detailing the impact of the Covenant War and the postwar status quo. In light of predicted resurgences of Covenant remnants and the Insurrection, as well as new discoveries regarding the Forerunners and their complex relationship with humanity, SURGEON hoped that future historians would view the war as an experience which served to strengthen the resolve of humanity as a whole and prepared them for even worse struggles yet to come.{{Ref/Reuse|EH}} This view echoes SURGEON's own conclusions regarding the Insurrection's impact on humanity's survival in the Covenant War in ''[[Historical/Psychological Analysis of Cole, Preston J.]]''<ref>'''Halo: Evolutions - Essential Tales of the Halo Universe''' - ''The Impossible Life and the Possible Death of Preston J. Cole'', ''page 457''</ref>

==Engagements==

{{Human-Covenant War}}

==Timeline==

{{Main|Timeline of the Human-Covenant War}}

==Non-canon and dubious canon appearances==

===Silver Timeline===

{{Main|Human-Covenant War/Silver}}

In the [[Silver Timeline]], [[The Rubble]] manages to survive for quite a bit longer through the war. As well, the [[Halo Array]] is discovered in a different manner.{{Ref/Site|Id=Debrief1|URL=https://www.halowaypoint.com/news/silver-debrief-a-new-beginning|Site=Halo Waypoint|Page=Silver Debrief: A New Beginning|D=9|M=3|Y=2022}} [[Operation]]s [[Operation: FALLEN WALLS|FALLEN WALLS]], [[Operation: HORIZON|HORIZON]] (on [[Algol]] rather than [[Cascade]]), and [[Operation: IRON FIST|IRON FIST]] took place in the timeline as well.{{Ref/Reuse|Halsey's Computer}}

[[Harvest]] was glassed by the Covenant prior to [[2540]].{{Ref/Site|Id=Halsey's Computer|URL=https://halotheseries.tv/|Site=Halo: The Series|Page=Dr. Catherine Halsey's Computer|D=25|M=3|Y=2022|LocalArchive=Dr. Catherine Halsey's Computer}} In [[2552]], the Covenant [[Attack on Madrigal|attacked]] [[Madrigal]] resulting in [[Silver Team/Silver|Silver Team]] being deployed to the planet.{{Ref/Generic|[[Halo: The Television Series]]|[[Contact]]}}

===Non-canon===

In the ''[[Halo Legends]]'' short ''[[Odd One Out]]'', UNSC forces fought Covenant forces on [[Cronkee]].

===Fracture: Entrenched===

The war between the Covenant and the UNSC in the [[Fractures|Entrenched fracture]] is known as the Final War.

*Admiral [[Preston Cole]] questioned the Covenant's apparent difficulty of finding Earth; he pointed out that they could have simply picked up human radio signals and triangulated the source. Cole theorized that the Covenant's systematic destruction of human colonies before assaulting Earth may have been due to an internal scheme within the upper tiers of the Covenant hierarchy that prevented Earth from being targeted sooner; that the destruction of the Outer Colonies before Earth was part of a religious ritual; or that the Covenant were not particularly interested in humanity's homeworld strategically, but for some other, unknown reason. Cole suspected that members of the Covenant military may not have been informed of the particulars of these underlying schemes; in order to prevent hypothetical "rogue elements" within the Covenant military from attacking Earth without authorization from the Covenant leadership, Cole recommended ONI to obfuscate human radio signals in slipspace.<ref>'''Halo: Evolutions - Essential Tales of the Halo Universe''', "The Impossible Life and the Possible Death of Preston J. Cole", ''page 469''</ref> Cole's speculations appear to have been at least partially correct; the Prophet of Truth had a far-reaching plan to increase his personal power, which involved keeping the other Hierarchs and most of the Covenant ignorant of key information, including the location of the human homeworld, until the optimal moment to strike Earth. Truth's plans were partially compromised when the Prophet of Regret discovered the location of the Ark Portal on his own and proceeded to attack Earth, unaware of the human presence.{{Ref/Reuse|tentwenty}} Despite Cole's theories, however, the possibility of triangulating Earth's position from radio signals does not appear to have occurred to the Hierarchs, as evidenced by Truth's more convoluted plan to have Kig-Yar led by [[Reth]] acquire navigation data leading to Earth from [[the Rubble]],<ref>'''Halo: The Cole Protocol''', ''page 285-286''</ref> and the fact that Truth did not discover Earth's location until 2552.{{Ref/Reuse|tentwenty}}

**''[[Halo 5: Guardians Limited Edition dossiers|Limited Edition dossiers]]'' {{Mo}}