Editing Battle of Installation 00

{{Era|HCW}}
{{disambig header|the final battle of the [[Human-Covenant War]]|other battles on Installation 00|Battle of Installation 00 (disambiguation)}}
{{Battle infobox
|prev=[[Battle for Earth]]
*[[Operation: MARSH FLASH]]
|conc=[[Operation: SUNSPEAR]]
|next=*[[Raid on UNSC Infinity]]
*[[Operation: FAR STORM]] {{c|[[Installation 00]]}}
|name=Battle of Installation 00
|image=[[File:H3 LesserArkConflict.png|400px]]
|conflict=*[[Human-Covenant War]]
*[[Great Schism]]
|date= [[2552#December|December 11, 2552]]{{Ref/Site|Id=Fortitude|URL=http://halo.xbox.com/en-us/Universe/detail/a/bfe5038b-314a-4f17-a6be-f7613e0e3788|Site=Halo Waypoint|Page=Hero-Fortitude|D=9|M=5|Y=2012|local=Heroes Never Die#Hero-Fortitude}}
|place= [[Installation 00]] {{c|the "Ark"}}
|result= '''Decisive [[United Nations Space Command|UNSC]]/[[Fleet of Retribution|Sangheili]] victory'''
*End of the [[Human-Covenant War]]{{Ref/Reuse|cov}}
*Death of the [[Prophet of Truth]]{{Ref/Reuse|cov}}
*Overall collapse of the [[Covenant]]{{Ref/Reuse|cov}}
*Truth prevented from firing the [[Halo Array]]{{Ref/Reuse|cov}}
*Flood-infested ''High Charity'' and Gravemind physically destroyed{{Ref/Reuse|cortana}}
*Proceeded with the [[Raid on Installation 08]], leading to the destruction of [[Installation 08]], severe damage to the Ark, and containment of the [[Flood]]{{Ref/Reuse|halo}}
|side1=*{{Icon|UNSC HCW}} [[United Nations Space Command|UNSC]]
**{{Icon|Navy}} [[UNSC Navy]]
**[[UNSC Marine Corps]]
**[[UNSC Air Force]]
*{{Icon|Covenant FB}} [[Covenant separatists]]
**[[Fleet of Retribution]]
*{{Icon|Forerunner}} [[Sentinel|Forerunner constructs]]
|side2=*{{Icon|Covenant FB}} [[Covenant]]†
|side3=*[[Flood]]
|commanders1=
*[[Commander|CDR]] [[Miranda Keyes]]†{{Ref/Reuse|theark}}
*[[Fleetmaster]] [[Rtas 'Vadum]]{{Ref/Reuse|theark}}
*[[Arbiter]] [[Thel 'Vadam]]{{Ref/Reuse|theark}}
*[[Sergeant Major|SGTMAJ]] [[Avery Johnson]]{{Ref/Reuse|theark}}
*[[Master Chief Petty Officer|MCPO]] [[John-117]]{{Ref/Reuse|theark}}
*[[Cortana]]{{Ref/Reuse|cortana}}
*[[000 Tragic Solitude]]
*[[343 Guilty Spark]]{{Ref/Reuse|theark}}
|commanders2=
*[[Hierarchs|High]] [[Prophet of Truth]]†
*[[Jiralhanae Chieftain|Chieftain]] [[Cethegus]]†{{Ref/Reuse|theark}}
*[[Shipmaster]] [[Hekabe]]{{Ref/Reuse|envoy}}
|commanders3=[[Gravemind]]†
|forces1=[[Fleet of Retribution]]/[[Seventh Fleet]]
*18+ ships{{Ref/NoteReuse|fleetnumber}}
**1 [[Sangheili]] [[battle group]]{{Ref/Note|Id=composition|See [[Fleet of Retribution#Notes|here]].}}
***1+ {{Class|CAS|assault carrier}}{{Ref/Reuse|theark}}
***9+ {{Class|CCS|battlecruiser}}s{{Ref/Reuse|theark}}
**[[Battle Group Victory]]
***2+ {{Class|Charon|light frigate}}s{{Ref/Reuse|theark}}{{Ref/Note|Id=AegisFate|Text=While [[Bungie]]'s [https://halo.bungie.net/News/content.aspx?type=topnews&link=Sandtrap_Postmortem Sandtrap postmortem] state that the ''[[Sandtrap]]'' (where the UNSC ''Aegis Fate'' stationed over the abandoned Jiralhanae base) took place on the "Waypoint" (which as later officially known as the Ark in ''Halo 3''), it is unknown if the map occurred during the Battle of Installation 00 but since it was originally intended by Bungie that the Ark would be [[Epilogue (Halo 3)|destroyed]] when [[Installation 08]] was prematurely activated as stated by [[Cortana]] in epilogue of ''Halo 3'', it is unlikely the map was intended to take place after the [[Raid on Installation 08]].}}
*Many air vehicles
**Numerous [[GA-TL1 Longsword]] fighters{{Ref/Reuse|theark}}
**Numerous [[D77-TC Pelican]]s
***[[D77H-TCI Pelican]]s{{Ref/Reuse|theark}}
**Numerous [[AV-14 Hornet]]s{{Ref/Reuse|theark}}
**1+ [[D96-TCE Albatross]]{{Ref/NoteReuse|AegisFate}}
**Many [[Seraph|T-31 Seraph]] fighters
***{{Pattern|Kai|Seraph}}s{{Ref/Reuse|theark}}
**Numerous [[Type-52 Phantom#Retribution Phantom|T-52 Phantom]]{{Ref/Reuse|cov}}
**Numerous [[Tarasque heavy fighter]]s
*Many ground forces
**1 [[SPARTAN-II program|SPARTAN-II supersoldier]]{{Ref/Reuse|theark}}
**Numerous [[UNSC Marine Corps|marines]]{{Ref/Reuse|theark}}
**Numerous [[Orbital Drop Shock Troopers|ODSTs]]{{Ref/Reuse|theark}}
**Numerous [[Sangheili]]{{Ref/Reuse|cov}}
*Ground vehicles
**Several [[M12 Warthog]]s
***[[M12 Chaingun Warthog]]s{{Ref/Reuse|theark}}
***[[M12G1 Gauss Warthog]]s{{Ref/Reuse|cov}}
**[[M274 Mongoose]]s{{Ref/Reuse|theark}}
**[[M808 Scorpion]]s
***[[M808C Scorpion]]s{{Ref/Reuse|theark}}
*Numerous [[Sentinels]]
**Numerous [[Aggressor Sentinel]]s{{Ref/Reuse|theark}}
**Numerous [[Constructor]]s{{Ref/Reuse|theark}}
**[[Forerunner automated turret|Automated turrets]]{{Ref/Reuse|theark}}
*[[Mendicant Bias]]
|forces2=[[Truth's fleet]]†
*53+ [[Covenant starship|ships]]{{Ref/Note|Id=fleetnumber|Text=See [[Truth's fleet#Notes|Truth's fleet's Notes section]] regarding the size of Truth's fleet and the joint UNSC-Sangheili combined fleet, which could indicate that the latter was larger than seen in ''[[The Ark]]'' level's opening cutscene (which only show 10 Sangheili ships and one [[UNSC Forward Unto Dawn|single frigate]] for unknown reasons) at least 18 ships and it is even possible that the combined fleet would comprise of 2 entire [[Fleet of Retribution|Sangheili]] and [[Battle Group Victory|UNSC]] [[battle group]]s, in case at least 16 Sangheili warships (as seen in the ''[[Heretic]]'' map during the chase for ''[[Indulgence of Conviction]]'') and at least 7 UNSC {{Class|Charon|light frigate}}s (as seen on ''[[Halo Mythos]]''), hence at least 23 allied ships and at least 69 Jiralhanae enemy ships for the Prophet of Truth's fleet assuming that Sangheili Major's report on the size of Truth's fleet is accurate.}}
**1 [[Forerunner]] [[keyship]]{{Ref/Note|Although present during the Battle of Installation 00, it did not participated in the [[space warfare|space battle]] over [[Installation 00]] as it landed on "[[Mahsko]]", a region of the Ark.}}
**3+ {{Class|CAS|assault carrier}}s{{Ref/Reuse|theark}}
**1+ {{Class|ORS|heavy cruiser}}{{Ref/Generic|Id=loot5|Heading=[[Halo Legendary Crate]]|Subheading=[[Halo Legendary Crate/Data Drops|Data Drop #5]]|Detail=[[:File:LC 05 Doc1.jpg|Apollo Leader To CDR S. Palmer]]}}{{Ref/Novel|Id=envoy|Novel=Halo: Envoy}}
**47+ [[Covenant cruiser|cruisers]]{{Ref/Level|Halo 3|[[Tsavo Highway]]}}{{Ref/Note|See [[Battle of Kenya#Notes|Battle of Kenya's Notes section]]}}
***Multiple {{Class|CCS|battlecruiser}}s{{Ref/Reuse|theark}}
**1+ [[Covenant frigate|frigate]]{{Ref/Reuse|loot5}}
*Many air vehicles
**Many [[Seraph|T-31 Seraph]] fighters
***{{Pattern|Kai|Seraph}}s{{Ref/Reuse|theark}}
**Many [[Type-26 Banshee|T-26 Banshees]]
***[[Type-26C Banshee|T-26C Banshees]]{{Ref/Reuse|theark}}
**Many [[Type-52 Phantom|T-52 Phantoms]]{{Ref/Reuse|theark}}
*Many ground vehicles
**3+ [[Type-47B Scarab|T-47B Scarabs]]{{Ref/Reuse|theark}}{{Ref/Reuse|cov}}
**[[Type-25 Chopper|T-25 Choppers]]{{Ref/Reuse|theark}}
**[[Type-26 Wraith|T-26 Wraiths]]{{Ref/Reuse|theark}}
***[[Type-52 Anti-Aircraft Wraith|T-52 AA Wraiths]]{{Ref/Reuse|theark}}
**[[Type-32 Ghost|T-32 Ghosts]]{{Ref/Reuse|theark}}
**[[Type-52 Prowler|T-52 Prowlers]]{{Ref/Reuse|theark}}
*Numerous ground forces{{Ref/Reuse|theark}}
**[[Jiralhanae]]
**[[Kig-Yar]]
**[[Unggoy]]
**[[Yanme'e]]
**[[Mgalekgolo]]
|forces3=*[[High Charity]]†{{Ref/Reuse|cov}}
*Multiple [[Flood dispersal pod|dispersal pods]]{{Ref/Reuse|cov}}
*Multiple [[Flood combat form|combat forms]]{{Ref/Reuse|cov}}
*Multiple [[Flood carrier form|carrier forms]]{{Ref/Reuse|cov}}
*Multiple [[pod infector]]s{{Ref/Reuse|cov}}
*Multiple [[Flood pure form|pure forms]]{{Ref/Reuse|cov}}
|casual1= Moderate
*[[Miranda Keyes]]{{Ref/Reuse|cov}}
*Unknown amount of Sangheili and human ships
*Numerous infantry losses
*Many Sentinels
|casual2=Near total
*[[Prophet of Truth]]{{Ref/Reuse|cov}}
*Most ships, if not all{{Ref/Reuse|theark}} {{c|save for ''[[Anodyne Spirit]]'' and ''[[Gathering of Praise]]''}}
*Most ground forces, if not all{{Ref/Reuse|cov}}
|casual3=Near total
*''[[High Charity]]''{{Ref/Reuse|cortana}}
*[[Gravemind]]{{Ref/Reuse|halo}}
}}
{{Quote|Our fight is through the [[Portal at Voi|Portal]], with the [[Jiralhanae|Brutes]] and the bastard [[Prophet of Truth|Truth]]!|[[Shipmaster]] [[Rtas 'Vadum]]{{Ref/Level|Id=floodgate|H3|Floodgate}}}}
The '''Battle of Installation 00''', also known as the '''Ark Conflict''',{{Ref/Book|Halo: Warfleet|Page=48}} and designated by [[United Nations Space Command]] forces as '''Operation: BLIND FAITH''',{{Ref/Book|Id=Blind Faith|Enc09|Page=57}}{{Ref/Book|Enc11|Page=29}} was a large [[battle]] between the UNSC-[[Fleet of Retribution]] alliance, the [[Covenant]], the [[Flood]], and [[Forerunner]] [[Sentinel]]s on [[2552#December|December 11, 2552]].{{Ref/Reuse|Fortitude}}{{Ref/Level|Id=theark|H3|The Ark (level)|The Ark}}{{Ref/Level|Id=cov|H3|The Covenant (level)|The Covenant}}{{Ref/Reuse|halo}} It was the final overarching battle of the [[Human-Covenant War]] and was the last stand of the Covenant,{{Ref/Reuse|halo}}{{Ref/Level|Id=epi|H3|Epilogue (Halo 3)|Epilogue}} making it one of the few major engagements in the entire war in which the Covenant were on the defensive.

After the [[Battle of the Citadel|collapse]] of the Covenant and the Battle of Installation 00, the [[Great Schism]] would continue as the [[Sangheili-Jiralhanae war]] and still ongoing as of [[2559]], after the [[Created]] [[Created conflict|uprising]] in [[2558#October|late 2558]].{{Ref/Novel|Evo|Section=The Return}}

==Background==
===Battle of Installation 04 and 05===
{{Main|Battle of Installation 04|Battle of Installation 05}}
During the [[Battle of Installation 04]] in September 2552, the [[United Nations Space Command|UNSC]] [[Artificial intelligence|AI]] [[Cortana]] intercepted the [[Installation]]'s [[Activation index|Index]] as it was being inserted by [[John-117]] into [[the Core]] in the [[Control Room (Installation 04)|control room]]. Having prevented the activation of the ring, she kept the index even after she had been removed from the Installation's control room. She had also spent over twelve hours inside the control room's computer, gaining an incredible amount of information about the [[Halo Array|Halo]] installations,{{Ref/Level|HCE|Assault on the Control Room}}{{Ref/Level|HCE|Two Betrayals}} making her possibly the most knowledgeable regarding the operation of the Halo rings, the Forerunners, and the Ark - perhaps even more so than [[343 Guilty Spark]], who admitted he was quite ignorant of the [[Forerunner]] structures beyond Installation 04.{{Ref/Reuse|theark}}

In November 2552, another battle on the next discovered Halo ring, the [[Battle of Installation 05]], included many events that would become major factors in the Battle of Installation 00. Cortana remained aboard the Covenant holy city, ''[[High Charity]]'', as the Flood and its central consciousness, the [[Gravemind]], took control of it.{{Ref/Level|Game=Halo 2|Level=[[High Charity (level)|High Charity]]}} From there, the Gravemind interrogated her, and she willingly answered its questions.{{Ref/Novel|Evo|Section=[[Human Weakness]]}} Meanwhile, the Covenant civil war, termed the [[Great Schism]], begun in ''High Charity'' and the space around Installation 05.{{Ref/Level|Game=Halo 2|Level=[[Gravemind (level)|Gravemind]]}} The recently-appointed Arbiter [[Thel 'Vadam]] and his Sangheili allies, in an effort to prevent [[Chieftain of the Jiralhanae]] [[Tartarus]] from activating the ring, formed an alliance with humans on the surface of Installation 05. With the help of Thel 'Vadam, [[Commander]] [[Miranda Keyes]] aborted the activation of Installation 05, but the installation's failsafe protocol had set all of the Halo rings to standby, where they could be activated from the central location of the Installation 00.{{Ref/Level|Id=TGJ|Game=Halo 2|Level=[[The Great Journey (level)|The Great Journey]]}} 

===Battle for Earth===
{{Main|Battle for Earth}}
Shortly after escaping the Flood on ''High Charity'', the [[Prophet of Truth|High Prophet of Truth]] had arrived on [[Earth]], along with the rest of many [[High Charity defense fleet|Covenant loyalist ground and naval survivors]] from the Battle of Installation 05,{{Ref/Reuse|TGJ}}{{Ref/Level|Id=Truthfleet|Game=Halo 3|Level=Crow's Nest|Quote=The Prophet of Truth's ships breached the Lunar perimeter. Smashed what was left of the Home Fleet.|Quotee=Miranda Keyes}} where the excavation of a [[Portal at Voi|Forerunner structure]] under the planet surface was almost completed by the Jiralhanae-led [[Truth's fleet|support and excavation fleet]] sent by Truth [[Battle of Mombasa|earlier]].{{Ref/Film|Id=waypoint|Film=Halo Waypoint|Story=Ten Twenty|StoryLinkText=Ten Twenty}} Eventually Truth's forces uncovered and activated the structure, opening a [[slipspace portal]] that would take them to Installation 00, the Forerunner structure from which Truth can fire all of the Halo installations at once. As he departed through the Portal, the Flood-captured ship ''[[Indulgence of Conviction]]'' arrived on Earth and crashed, though its arrival was followed by a portion of the Sangheili [[Fleet of Retribution]] of at least 16 [[Covenant starship|warships]], led by [[Shipmaster]] [[Rtas 'Vadum]].{{Ref/Level|Halo 3|[[The Storm]]}}{{Ref/Map|Id=heretic|H3|Heretic}} From it, John-117 was able to extract a message from [[Cortana]], alerting them that ''High Charity'' was heading for Earth and cryptically stating that [[Installation 08|the "solution" to the problem of the Flood]] lays beyond the portal.{{Ref/Reuse|floodgate}}

While [[Terrence Hood|Lord Terrence Hood]] was suspicious of Cortana's warning and objected to going through the portal, Commander Keyes, John-117, and Rtas 'Vadum all indicated their wish to proceed through the Portal. Unwilling to leave Earth defenseless against the incoming Flood threat, Lord Hood remained on Earth. He gave Miranda Keyes command of the {{UNSCShip|Forward Unto Dawn}} for the human commitment to the mission and the fleet of ships chased after the High Prophet of Truth.{{Ref/Reuse|floodgate}}

==Battle==
===Space battle===
[[File:H3 - Retribution Victory vs Truths Fleet.png|thumb|300px|Truth's Jiralhanae fleet confronts the Sangheili Fleet of Retribution]]
{{Quote|multi=yes|q1=Brute ships. Staggered line! Shipmaster, they outnumber us, three-to-one!|Sangheili Major|q2=Then it is an even fight... All cruisers, fire at will! Burn their mongrel hides!|Rtas 'Vadum|Rtas' Vadum and a [[Sangheili Major]] upon reaching the Ark.{{Ref/Reuse|theark}}}}

The Fleet of Retribution exited slipspace in the vicinity of the Ark on [[2552#December|December 11, 2552]], where they found [[Truth's fleet|the Prophet of Truth's fleet]] waiting for them. Despite being outnumbered three-to-one, Rtas 'Vadum declared that they were fairly matched, and the Sangheili ships and the ''Forward Unto Dawn'' promptly engaged Truth's fleet. In the ensuing [[space warfare|space battle]], the Jiralhanae and Sangheili cruisers blended into each other.{{Ref/Level|H3|The Ark (level)|The Ark|Quote=Their cruisers mixed with ours! Watch your fire!|Quotee=Jiralhanae Commander}} 'Vadum and Keyes coordinated their attacks against the Covenant fleet; whereas the Sangheili ships and the ''Dawn'' focused their attacks on the Covenant cruisers,{{Ref/Level|H3|The Ark (level)|The Ark|Quote=Let the Elites handle those cruisers!|Quotee=Miranda Keyes}} the ''Dawn''{{'}}s Longsword fighters engaged the Seraphs.{{Ref/Level|H3|The Ark (level)|The Ark|Quote=Stay away from those cruisers!|Quotee=Rtas 'Vadum}}{{Ref/Level|H3|The Ark (level)|The Ark|Quote=Understood. Engage those Seraphs!|Quotee=Miranda Keyes}} However, the ''Dawn'' was ill-equipped to fight against large opponents like ''CAS''-class assault carriers and ''CCS''-class battlecruisers. Thus, at the start of the battle, the ''Dawn'' deployed six [[D77H-TCI Pelican]]s to the surface to search for a landing zone for the ''Dawn'' and gather intelligence on Truth's location.{{Ref/Reuse|theark}}

The Forerunner [[Keyship]], ''[[Anodyne Spirit]]'', did not participate in the space battle.{{Ref/Reuse|theark}} Instead, it landed amidst a Forerunner city within a region of the Ark later referred to as [[Mahsko]] by the [[Banished]].{{Ref/Reuse|Id=Sacrifice}} A detachment of Covenant warriors were assigned to protect the vessel as Truth left to activate the [[Halo Array]].{{Ref/Novel|Id=Sacrifice|HSoR|Detail= Adjunct - [[Sacrifice]]}}

Although the space battle went on concurrently with the opening skirmishes on the surface of the Ark, the Sangheili fleet would make short work of the Covenant fleet due to the Jiralhanae being outmatched by the Sangheili in their knowledge of naval warfare.{{Ref/Book|Id=Mythos122|Halo Mythos: A Guide to the Story of Halo|Page=122}} At least two Sangheili ships would survive the battle: the flagship ''CAS''-class assault carrier ''[[Shadow of Intent]]'' and the ''CCS''-class battlecruiser ''[[Pious Inquisitor]]''.{{Ref/Reuse|theark}}{{Ref/Novel|Halo: The Thursday War|Chapter=?}} On the Covenant side, the {{Class|ORS|heavy cruiser}} ''[[Foebane|Gathering of Praise]]'', led by [[Jiralhanae Chieftain]] [[Hekabe]], abandoned the Covenant forces and landed on the installation surface in search of a device known as the ''[[vertex]]''.{{Ref/Reuse|envoy}}

{{clear|left}}
===Search for the Cartographer===
{{Main|Battle for the Cartographer (Installation 00)}}
[[File:Ark Level Scorpion.jpg|thumb|left|300px|UNSC ground forces battling in the desert.]]
The Pelicans from the ''Forward Unto Dawn'' arrived on the surface of the Ark, where they deployed [[UNSC Marine Corps|Marines]] and UNSC vehicles to search for a landing zone for the ''Dawn''. ''[[Kilo 023]]'' and another Pelican deployed [[Master Chief Petty Officer]] John-117 and a squad of [[Orbital Drop Shock Trooper|ODSTs]] at a cliff edge, near a series of Forerunner structures built into the desert terrain. Nearby, a third Pelican, which carried a [[M12 Chaingun Warthog|Warthog]], two [[M274 Mongoose|Mongooses]], and [[UNSC Marine Corps|Marines]] including [[Chips Dubbo]], found a wide cliff which could serve as a landing zone for the ''Dawn'', but the Pelican was shot down by Covenant anti-air defenses.{{Ref/Reuse|theark}}

With support from his accompanying ODST squad and his [[SRS99D-S2 AM sniper rifle]], John-117 cleared out two Covenant camps of Jiralhanae, Unggoy, and Kig-Yar. At the second camp, they disrupted the Covenant's efforts to assemble a [[Type-27 Mantis|Mantis]]. Emerging on the other side of the Forerunner structures, they linked up with Dubbo and other survivors seeking refuge from the downed Pelican, where a lance of Covenant searched for survivors. Dubbo informed John-117 of the potential landing zone for the ''Dawn''. Upon defeating the Covenant patrol at the Pelican, a pair of [[Type-52 Prowler|Prowlers]] arrived at the area, but their operators were eliminated by the UNSC. Salvaging both UNSC and Covenant vehicles, John-117 and his team advanced into the Covenant-occupied canyon. At this point, the Covenant have set up an attack force of infantry and [[Type-26 Shade]]s at a nearby [[Forerunner]] wall, which was defended by [[Aggressor Sentinel]]s. John-117 and his team eliminated the Covenant attackers, and the Sentinels, recognizing the humans as [[Reclaimer]]s, withheld their attacks. [[Sergeant Major]] [[Avery Johnson]], onboard ''Kilo 023'', spotted a structure that was similar to the [[Cartographer]] of [[Installation 04]] on the other side of the wall, and Keyes set the structure as the objective.{{Ref/Reuse|theark}}

The landing zone was occupied by Ghosts, a [[Type-26 Wraith|Wraith]], several [[deployable lookout tower]]s, Jiralhanae and Unggoy infantries, and two [[Type-52 Anti-Aircraft Wraith|Anti-Air Wraiths]] that were firing into an aerial battle between [[Type-26 Banshee|Banshees]] and [[AV-14 Hornet|Hornets]]. John-117 and his team, having gathered more Marine survivors, cleared the landing zone, allowing the ''Forward Unto Dawn'' to disengage from the space battle and descend to the surface of the installation, landing safely. From the ''Dawn''{{'}}s hangar, the UNSC was reinforced with three [[M808C Scorpion|Scorpion]] tanks, a [[M12 Chaingun Warthog|Warthog]] and a unit of Marines led by [[Gunnery Sergeant]] [[Marcus Stacker]]. With [[343 Guilty Spark]] having arrived to guide them, the mechanized force then fought their way back to the Forerunner wall, destroying numerous Covenant vehicles and ground troops. The Covenant had retaken the wall, bolstering their defenses with Wraiths, Choppers, and Shade turrets, but they failed to deter the UNSC's progress.{{Ref/Reuse|theark}} 

After entering the wall and emerging from the other side, the UNSC encountered a [[Type-47B Scarab|Scarab]]. Although the Scarab quickly left the area, the canyon leading from the wall to the Cartographer was defended by a battalion-sized force of Covenant heavy armor, including Choppers, Ghosts, Wraiths, and infantry with [[Type-33 fuel rod gun|heavy weapons]], reinforced by a Phantom. Two of the three Warthogs, which emerged from the wall first, were quickly overwhelmed, and their operators were killed. A single [[M12G1 Gauss Warthog]], taking a winding path to the side, was harassed by Ghosts and lost its gunner, though it regrouped with John-117, who had left the group earlier when they travel across the wall. The Spartan commandeered the vehicle and rejoined the Scorpion tanks. John-117 and Stacker then led the Scorpions against the Covenant armor. When the UNSC forces broke through the Covenant defenses, the Scarab returned to the area, with Choppers as its escorts. Stacker ordered Marines from Bravo unit to flank the Scarab to cover John-117's assault on the Scarab. They succeed, with John-117 personally taking down the Scarab. After the Scarab's destruction, the ''[[Shadow of Intent]]'' arrived at the Cartographer, and Rtas 'Vadum announced that his fleet had destroyed Truth's fleet.{{Ref/Reuse|theark}}

[[File:H3 TanksVsScarab.png|300px|thumb|right|Scorpion Tanks battle a Scarab in the desert.]]

Encountering resistance from Jiralhanae and Kig-Yar on the way, John-117 climbed a series of ramps towards the entrance to the Cartographer. At the top, he met with [[Thel 'Vadam]], who dismounted from ''Kilo 023'' along with a pair of Marines. While Commander Keyes assembled an air support force to prevent Covenant reinforcements, 343 Guilty Spark unlocked the sealed door at the entrance, allowing John-117 and Thel 'Vadam to advance inside. Their arrival caught most of its Covenant occupants off-guard, and they eventually arrived at an exterior platform hosting the Cartographer terminal. The Chief and 343 Guilty Spark accessed the terminal, learning the installation as the "Ark" and that Truth had already fortified himself at [[Installation 00 Citadel|the core of the Ark]], where he could remotely activate the entire Halo Array. Furthermore, Truth had activated a large barrier around the entire core to ward off the attacking forces.{{Ref/Reuse|theark}}

After learning of Truth's location, they were attacked by a Phantom, one of the many aircrafts from the Covenant's aerial attack on the Cartographer. Thel 'Vadam drew the Phantom's fire, allowing the Chief to escort Spark clear. 'Vadam then hijacked a Banshee and joined Keyes' air support to repel the Covenant attack. Notified by Dubbo, John-117 was instructed to descend to a platform underneath the Cartographer for extraction. The Spartan fought his way down, defeating a [[Jiralhanae War Chieftain|War Chieftain]], his [[Jiralhanae Bodyguard|Bodyguards]], and a group of [[Cloaking|camouflaged]] [[Jiralhanae Stalker]]s along the way.{{Ref/Reuse|theark}} At the platform underneath the Cartographer terminal, [[Jiralhanae Chieftain]] [[Cethegus]] regrouped with the [[Jiralhanae Jumper|Jumpers]] from his pack. Cethegus and the members of his pack were charged with halting the UNSC-Sangheili progress. Believing he would ascend to the title of Chieftain of the Jiralhanae for killing the Spartan, the ambitious Chieftain challenged John-117 to a duel.{{Ref/Site|URL=https://www.halowaypoint.com/en-us/news/canon-fodder-brute-force|Site=Halo Waypoint|Page=Canon Fodder - Brute Force|D=11|M=10|Y=2021}} Despite being outnumbered, John-117 defeated Cethegus' pack as well as two Kig-Yar marksmen. Meanwhile, the Hornets under Keyes' command have destroyed the Banshee attack force, putting an end to the conflict at the Cartographer.{{Ref/Reuse|theark}}

''Kilo 023'' arrived to pick up John-117, but a massive swarm of Sentinels approached the Pelicans. Initially, the UNSC prepared to attack, but they stopped when 343 Guilty Spark asked them not to attack the Sentinels, stating that the Sentinels had a "priority task" of unknown nature. Instead of attacking, the Aggressors flew off into the distance, and the UNSC and Sangheili followed suit, making their way to the Installation 00 Citadel to stop the Prophet of Truth.{{Ref/Reuse|theark}}

{{clear|left}}

===Battle of the Citadel===
{{main|Battle of the Citadel}}
[[File:Trident11.jpg|thumb|left|300px|UNSC and Sangheili forces spearhead their final assault on the High Prophet of Truth.]]

On the same day, December 11, 2552, the UNSC-Sangheili alliance arrived at vicinity of the core of Installation 00. AV-14 Hornets were sent in to contest for airspace around the barrier. An assault team, composed of five Pelican dropships and a pair of Sangheili Phantoms, began their attack on a trio of [[Barrier tower|towers]] that, once disabled, would deactivate the barrier protecting the Citadel in which the Prophet of Truth was located. Two Pelicans, including ''Kilo 023'' which carried John-117 and an ODST squad led by Gunnery Sergeant Stacker, would attack the Tower One. The Phantoms, which carried Thel 'Vadam and his Sangheili (including [[N'tho 'Sraom]] and [[Usze 'Taham]]),{{Ref/Novel|Halo: Hunters in the Dark|Chapter=?}} would assault the middle tower. The other Pelicans, ferrying Sergeant Johnson and his squad, would disable the final tower. ''Kilo 023'' deployed John-117, along with Stacker and his ODSTs, at a distance from the first tower after an Anti-Aircraft Wraith shot down the second Pelican carrying Marines and a Warthog. After John-117 defeated the War Chieftain, his entourage, and the Anti-Air Wraith, Commander Keyes' Pelican deployed a new Warthog and a Mongoose at the beachhead for the team. Meanwhile, the ''Shadow of Intent'' began a diversionary bombardment against the barrier, firing [[plasma torpedo]]es at the barrier shield.{{Ref/Reuse|cov}}

While John-117 and his team traveled to the first tower, 'Vadam and Johnson, along with their teams, touched down at the second and third towers, respectively. Although John-117 and 'Vadam succeed in disabling two of the three towers, Johnson was ambushed by enemy reinforcements, and lost contact with the UNSC soon after. The Jiralhanae captured Johnson, and took him to the Citadel. The UNSC-Sangheili forces launched a second assault on the third tower, with John-117 escorting the dropships in an AV-14 Hornet. They first destroyed Covenant Banshees and a Phantom, securing air control outside the barrier. The third tower was heavily defended by a pair of AA Wraiths, Shades, another standard Wraith, and a huge group of Jiralhanae led by War Chieftain. Destroying the Brute defenders outside the third tower, John-117, Thel 'Vadam, and a team of five Sangheili proceeded inside, where they discovered the corpses of Johnson's team, except for Johnson. After the defending forces of Mgalekgolo, Yanme'e and Jiralhanae were eliminated, John-117 disabled the barrier tower, finally deactivating the barrier. The ''Shadow of Intent'' advanced towards the Citadel, but 'Vadum's attack was interrupted by the arrival of the Flood-infested ''High Charity'', which arrived via slipspace. ''High Charity'' launched debris that crippled the carrier and its weapons systems, forcing the ''Shadow of Intent'' to retreat. It also launched [[Flood dispersal pod]]s and began spreading Flood across the Ark. Keyes insisted that the Flood's arrival would only pressure Truth into activating the rings, and ordered the remaining ground forces to attack the Citadel.{{Ref/Reuse|cov}}

[[File:H3 CitadelBattle.jpg|300px|thumb|right|The massive final battle of the Human-Covenant War at the front of the Citadel.]] 

During this time, the [[Jiralhanae Chieftain]] [[Hekabe]] decided to use the distraction from the Flood arrival to locate the ''[[vertex]]'' hidden on the Ark. The control device for the [[Sharquoi]], the ''vertex'' would allow Hekabe to control the creatures. Though the Prophets had some Sharquoi themselves, they had lacked the ''vertex'' and so could not control them and never unleashed them. Hekabe intended to use the ''vertex'' and the Sharquoi to gain power for himself and so fled the Ark with his loyalists before the battle ended despite fighting on the side of the Covenant.{{Ref/Reuse|envoy}}

Fighting through the Flood to exit the third tower, John-117 and the Sangheili regrouped with Gunnery Sergeant Stacker's Marines, now supported by a Scorpion, a Gauss Warthog, and a Mongoose. The humans and Sangheili fought through the cliffs to the area outside the Citadel, where the Covenant have set up lookout towers, Shade turrets, and ground vehicles. The Covenant attempted to reinforce their troops by a large amount of Banshees, but the UNSC air forces counterattacked with Hornets and Pelican gunships. The ground forces led by John-117 punched through the remaining Covenant armor on the mountainside. With the UNSC's arrival imminent, the Covenant deployed two final Scarabs, each commanded by a Jiralhanae War Chieftain, at the entrance to the Citadel, further supported by Prowlers, Ghosts, and Banshees. However, their efforts were in vain, and, with the Scarabs destroyed by John-117, any remaining Covenant stragglers were soon moped up by the UNSC.{{Ref/Reuse|cov}}

While the Flood began climbing up the Citadel's far wall, John-117 and Thel 'Vadam led a small attack force, including N'tho 'Sraom, Usze 'Taham, as well as a few Marines and Sangheili, into the Citadel.{{Ref/Novel|Id=HitD252|Halo: Hunters in the Dark|Page=252}} Inside, the Prophet of Truth was giving a speech attempting to reassure his remaining followers, declaring that he was about to activate the Halo Array by forcing Johnson into interacting the control panel. Realizing that they had very little time left, John-117 and Thel 'Vadam hastily made their way to the elevator that would carry them to Truth's level, but the elevator's immense height meant that they would not be able to intervene in time.{{Ref/Reuse|cov}}

Johnson attempted to goad the Chieftain that was holding him into killing him, but Truth, realizing this, stopped the Chieftain. With John-117 and the Arbiter too far away to stop Truth, Commander Keyes took her Pelican dropship and crashed it directly into the facility in an attempt to rescue Johnson, but she was killed by Truth himself when she hesitated to kill Johnson and herself to deny Truth a means to activate the rings. Johnson, struck by grief and shock, was easily made to activate the Array. However, Keyes' actions delayed Truth long enough for John-117 and the Arbiter to stop him. The Gravemind dispatched a swarm of [[Pod infector]]s and [[Flood combat form]]s, led by two [[Flood tank form]]s, to assist the UNSC-Sangheili force in preventing the Halos' activation. They were met by the Jiralhanae Chieftain and his Unggoy, Kig-Yar and Jiralhanae.{{Ref/Reuse|cov}}

[[File:TruthDeath-large.jpg|thumb|left|300px|Arbiter killing the High Prophet of Truth.]]
The defending Covenant forces quickly collapsed under the combined assault from the humans, Sangheili, and the Flood. With all Covenant in the Citadel eliminated, John-117 and 'Vadam reached the final room where they found Johnson cradling the dead body of Commander Miranda Keyes. 'Vadam confronted the Prophet of Truth, who was already partially infected by the Flood. 'Vadam allowed the Prophet to live long enough to see John-117 deactivate the rings, and 'Vadam personally killed Truth. With the Halo threat eliminated, the Gravemind betrayed the humans and the Sangheili, sending a large group of Flood combat forms and carrier forms after John-117 and Thel 'Vadam. The two attempted to escape on Keyes' Pelican, now piloted by Johnson, but they were knocked off by one of Gravemind's tentacles. With Johnson's Pelican spiraling out of the control, Johnson instructed the two to return to the elevator.{{Ref/Reuse|cov}}

With the assistance of Aggressor Sentinels, the pair fought their way back to the elevator, which had been disabled. Without another choice, the two dropped down a small shaft in the room. At the bottom, John-117 followed flickers of Cortana to a control panel, and, upon its activation, they found [[Installation 08]] departing from the Ark's [[Foundry (location)|Foundry]]. Realizing this was Cortana's "solution" for the Flood, John-117 decided he needed to activate the ring at the Ark's isolated location, where the pulse would not destroy the sentient life in the [[Milky Way]] galaxy. 343 Guilty Spark concurred, that a tactical pulse would eliminate the Flood infestation on the Ark, and made his way to the ring to oversee the final preparations. However, this new Halo lacked an activation index. The only way they could get another index was to rescue Cortana from ''High Charity'', since she still possessed the index from the original Installation 04.{{Ref/Reuse|cov}}

===Master Chief's raid on ''High Charity''===
{{Main|Raid on High Charity}}
While Johnson, 'Vadam, and 'Vadum rounded up the UNSC and Sangheili survivors from the battle, John-117 took a Banshee and [[Raid on High Charity|infiltrated]] the Flood-infested ''High Charity''. The Spartan fought through swarms of Flood and successfully recovered Cortana, who indeed still held the activation index from Installation 04. Under Cortana's guidance, John-117 sabotaged the city's reactors, causing a series of explosions that crippled the Gravemind and destroyed ''High Charity''. 'Vadam arrived shortly after, and the trio fled onboard a crashed Pelican.{{Ref/Level|Id=cortana|H3|Cortana (level)|Cortana}}

{{clear|left}}

===Finishing the fight===
{{Main|Raid on Installation 08}}
[[File:Halo3Mythos.jpg|thumb|300px|John-117, Thel 'Vadam, Sergeant Major Avery Johnson, and 343 Guilty Spark on the surface of Installation 08.]]
{{Quote|multi=yes|q1=We are aboard, humans...and Elites. Will you not come with us, brother?|Rtas 'Vadum|q2=No. This is our fight. And I ''will'' see it finished.|Thel 'Vadam|Thel 'Vadam wishing to finish the fight alongside John-117.{{Ref/Reuse|halo}}}}
With the index secured, Thel 'Vadam ordered Rtas 'Vadum to take the human and Sangheili survivors to leave the Ark, using the slipspace portal to Earth. 'Vadam accompanied John-117 and Cortnaa to the incomplete Halo. Sergeant Major Johnson piloted the UNSC ''Forward Unto Dawn'', which was left behind for their escape, to a safe location near the control room, then drove a Warthog to the control room. The Gravemind, meanwhile, had begun to rebuild itself on the new ring, and sent [[Flood dispersal pod]]s to stop the three interlopers. John-117, 'Vadam, and Johnson, with the assistance of local Sentinels, fought through the Flood and entered the Control Room. Inside, Spark explained that the new Halo would be ready to fire within days, to which the group, particularly Johnson, protested. When Guilty Spark informed the three that activating Halo now would destroy both the Ark and the installation, Johnson told him to "deal with it" and prepared to activate the ring.{{Ref/Reuse|halo}}

Unwilling to let "his" ring be destroyed again, 343 Guilty Spark attacked the trio. He mortally wounded Johnson, took down the Master Chief's shields, and blew 'Vadam out of the room. Spark cornered John-117, but with the help of Johnson and his [[M6 Spartan Laser|Spartan Laser]], John-117 defeated Guilty Spark and initiated the firing sequence of the new Halo. The incomplete Halo began ripping itself apart under the charging sequence. Fighting past the Flood and the Sentinels that have turned on them, John-117 and 'Vadam took Johnson's Warthog and rushed towards the ''Dawn'' as the incomplete Halo powered up and started breaking apart. The two drove their way through hordes of battling Flood and Sentinels. The two made it onto the ''Dawn''{{'}}s hangar bay, from where 'Vadam ran to the bridge while John-117 inserted Cortana into a holotank in the hangar bay, so she could activate the ''Dawn''{{'}}s engines. The ''Dawn'' left the ring just as it fired.{{Ref/Level|Id=halo|H3|Halo (Halo 3 level)|Halo}} The firing sequence shook the ring into pieces and heavily damaged Installation 00. The Slipspace portal collapsed as the ''Dawn'' entered it, and while the forward half with 'Vadam made it to Earth, the rear half fell out of Slipspace at an unknown location, leaving John-117 and Cortana stranded in space.{{Ref/Reuse|epi}}

==Aftermath==

===The Flood===
[[File:HaloLegends-Origins-ArkHalo.png|250px|thumb|right|Installation 08 fires and crumbles over the Ark, severely damaging everything on its surface.]]
On December 14, 2552, just three days after the battle and the ring's activation, 000 Tragic Solitude marshalled his Sentinels to construct a [[containment shield]] around the remains of ''High Charity's'' ruins, in fear that any few surviving Flood remnants would escape the crash site. Furthermore, he instructed his Sentinels to raze perimeter, and the local [[refugia]] modified to ensure no nearby [[Sentience|sentient]] life survived, thus depriving the Flood of any host bodies in close proximity.{{Ref/Game|Id=idle hands ii|HW2|Section=Phoenix Log#The Archive 2|SectionLinkText=Phoenix Log – "Idle Hands II"}} By [[2553#February|February 19, 2553]], the Flood remnants were contained within the rubble of ''High Charity'',{{Ref/Game|Id=uncomfortable i|HW2|Section=Phoenix Log#Manifestation 2|SectionLinkText=Phoenix Log – "An Uncomfortable Truth I"}} with a [[battalion]] of Sentinels patrolling in the vicinity of the shield to prevent both the Flood from escaping and future "invaders" from releasing them.{{Ref/Reuse|idle hands ii}} 

However, their defenses were proven to be ineffective, with the [[Banished]] forces led by Jiralhanae [[Voridus]] [[Outbreak on Installation 00|releasing the Flood]] from the ruins of ''High Charity'' and providing them with hosts to infect during the [[Second Ark Conflict]] in [[2559#June|June 4, 2559]].{{Ref/Reuse|wrong}} This inadvertently caused a Flood outbreak onto the installation, leading to a desperate struggle between the Banished and the parasite. Ultimately, the Banished managed to destroy a [[Proto-Gravemind]] that was moments away from becoming a Gravemind and the Ark's Sentinels and the Banished managed to once again contain the Flood.{{Ref/Level|HW2|Manifestation}}

===The Covenant===
{{Main|Covenant loyalists|Covenant remnants}}
Despite the death of Truth and the vast majority of his forces, as well as the ravaging of the Ark, a [[Covenant loyalists|small sliver of the Jiralhanae loyalist forces]] remained inside the ''Anodyne Spirit'' which shielded them for the firing of [[Installation 08]]. The survivors guarded it for years using stocked supplies and Covenant issued equipment{{Ref/Reuse|Id=Sacrifice}} and had access to numerous Covenant era vehicles.{{Ref/Reuse|Id=divinechapt2}}

Although the Battle of Installation 00 marked the end of the Human-Covenant War, numerous new [[Covenant remnants|splinter factions from the Covenant]] were created in its wake. These factions ranged from pragmatic mercenaries to fanatical religious cultists.{{Ref/Comic|Halo: Escalation|Issue=[[Halo: Escalation Issue 5|5]]}} These factions would come into [[Post-Covenant War conflicts|conflict with each other]], notably [[Sangheili-Jiralhanae war|a war between the Sangheili and the Jiralhanae]] following the Great Schism, and [[Blooding Years|numerous civil conflicts]] fought between the Swords of Sanghelios and various other Sangheili factions.{{Ref/Site|URL=https://www.halowaypoint.com/en-us/universe/locations/sanghelios|Site=Halo Waypoint|Page=Universe - Locations - Sanghelios|D=20|M=10|Y=2021}}

===''UNSC Forward Unto Dawn''===
{{Main|Battle of Requiem}}
The Portal between Installation 00 and Earth collapsed while {{UNSCShip|Forward Unto Dawn}} was still inside it. As a result, the ship was cut in half; the front arriving at Earth and the back half being lost in space. Thel 'Vadam, sitting on the bridge at the time, was part of the front half but, without any engines, soon crashed into the ocean, from where he was rescued by UNSC forces on Earth. John-117 and Cortana were in the rear half, and though they survived the Portal’s collapse, they were stranded in space and declared MIA. John-117 went into cryo-sleep while Cortana activated a [[distress beacon]] indicating their status.{{Ref/Reuse|epi}} After drifting in an unknown region of space for over four years until [[2557#July|2557]],{{Ref/Level|H4|Dawn (level)|Dawn}} the rear half of the ''Dawn'' was caught in the [[gravity well]] of a Forerunner [[shield world]] known as [[Requiem]],{{Ref/Level|Id=H4|H4|Requiem (level)|Requiem}} where they would come into [[Battle of Requiem|conflict]] with [[Jul 'Mdama's Covenant]].{{Ref/Reuse|H4}}

==Legacy==
{{Quote|For us, the storm has passed. The war is over. But let us never forget those who journeyed into the howling dark, and did not return. For their decision required courage beyond measure; sacrifice, and unshakable conviction that their fight, our fight, was elsewhere. As we start to rebuild, this hillside will remain barren. A memorial to heroes fallen. They ennobled all of us, and they shall not be forgotten.|[[Fleet Admiral]] [[Terrence Hood]] in the memorial ceremony{{Ref/Reuse|epi}}}}
A [[Voi Memorial|monument]] was made near the town of Voi, not far from the portal structure. It read, "''In memory of those fallen in the defense of Earth and her Colonies. [[2553|March 3, 2553]].''" On it were photos of UNSC personnel who went through the portal but did not return; John-117 was honored with an etching of the number "117". With the exception of Thel 'Vadam, the Sangheili were not present at the dedication service, instead remaining aboard ''Shadow of Intent''. After the ceremony, Lord Hood, despite being unable to forgive the Sangheili for what they did to humanity at the beginning of the war, shook 'Vadam's hand and thanked him for standing beside the Master Chief at the Ark. The Arbiter then joined [[Rtas 'Vadum]] on the bridge of ''Shadow of Intent'', both agreeing to return to [[Sanghelios]] to ensure its safety. Thel 'Vadam was given command of the carrier and all Sangheili onboard departed for their homeworld.{{Ref/Reuse|epi}}

===Installation 00===
{{Quote|no=three|1=Jerome-092|q1=Isabel, where did all this wreckage come from?|2=Isabel|q2=There was a battle here near the end of the war. The Master Chief saved us all.|3=Jerome-092|q3=It's good to know John's still out there.|4=[[Isabel]] and [[Jerome-092]] while fighting the [[Banished]] on Installation 00.{{Ref/Reuse|HW2}}}}
The wreckage from the Battle of Installation 00 remained on the surface of the Ark.{{Ref/Level|Id=HW2|HW2|A New Enemy}}{{Ref/Level|Id=wrong|HW2|What Could Go Wrong?}} Over two years later on [[2555|March 20, 2555]], during [[Operation: FAR STORM]], [[Luther Mann]] and [[N'tho 'Sraom]] arrived at the Citadel to stop the Halos from firing. Scattered around the basin were the remains of human and Covenant vehicles left over from the battle, including the empty husks of the two [[Type-47B Scarab|Scarabs]].{{Ref/Reuse|HitD252}} The firing of the Halo ring caused unprecedented damage to the Ark while sterilizing most of the Flood forces around and on the installation, including the Gravemind commanding the massing Flood amid the battle. Installation 00 was severely damaged,{{Ref/Reuse|epi}} and its monitor [[000 Tragic Solitude]], although inflicted with a state of [[rampancy]] from the ring's explosion, began repairing the installation.{{Ref/Book|Halo Mythos: A Guide to the Story of Halo|Page=154-155}} 

In [[2555#March|March 2555]], 000 Tragic Solitude sought revenge against humanity for damaging the Ark years prior. To do so, the ancilla placed the remaining Halos on a brief countdown to activation, prompting a joint UNSC-[[Swords of Sanghelios]] [[Operation: FAR STORM|mission]] to the installation to stop the rings from firing. After Solitude's plan was thwarted, the UNSC established research facilities on the Ark.{{Ref/Novel|Halo: Hunters in the Dark|Page=?}} The UNSC's research team was able to repair the Ark from the damage done in the battle by directing the Ark's [[Retriever Sentinel]]s to mine lifeless systems for the needed materials for repairs.{{Ref/Game|HW2|Section=Phoenix Log#The Signal 2|SectionLinkText=Phoenix Logs - "The Healing of Old Wounds"}}

In [[2558#September|September 2558]], the [[Jiralhanae Chieftain]] [[Hekabe]] attempted to unleash the [[Sharquoi]] on the planet [[Carrow]], having retrieved the Sharquoi control device, the ''[[vertex]]'', from the Ark during the Battle of Installation 00. Hekabe's plan was narrowly foiled by [[Gray Team]], [[Rojka 'Kasaan]] and elements of the [[Surakan Militia Volunteers]].{{Ref/Reuse|envoy}}

The [[Banished]] arrived on the fully repaired Ark in [[2558#November|November 2558]], killing UNSC personnel across the installation. In [[2559#March|March 2559]], the crew of the newly arrived {{UNSCShip|Spirit of Fire}} [[Second Ark Conflict|engaged]] the Banished with help from [[Isabel]], the logistics AI of [[Henry Lamb Research Facility|one of the UNSC research facilities]].{{Ref/Reuse|HW2}} Over the course of the battle they would engage not only the Banished, but the few surviving Covenant forces under the command of  and forces from the [[Keepers of the One Freedom]].{{Ref/Novel|Id=divinechapt2|Halo: Divine Wind|Chapter=2}}

==Participants==
{{col-begin}}
{{col-2}}
===UNSC===
===Naval assets===
====Starships====
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Tactical grouping
! Class
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
| rowspan="2" | [[Seventh Fleet]]
| rowspan="2" | {{Class|Charon|light frigate}}
|{{UNSCShip|Forward Unto Dawn}}
|Destroyed, split in half
|-
|{{UNSCShip|Aegis Fate}}{{Ref/NoteReuse|AegisFate}}
|Unknown
|}

====Military personnel====
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Branch
! Rank
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
| rowspan="3" |[[UNSC Navy]]
|[[Master Chief Petty Officer]]
|[[John-117]]{{Ref/Reuse|theark}}
|Survived, listed as MIA
|-
|[[Commander]]
|[[Miranda Keyes]]{{Ref/Reuse|theark}}
|KIA
|-
|[[Lieutenant]]
|[[Hocus]]{{Ref/Reuse|theark}}
|Unknown
|-
| rowspan="3" |[[UNSC Marine Corps]]
|[[Sergeant Major]]
|[[Avery Johnson]]{{Ref/Reuse|theark}}
|KIA
|-
|[[Private First Class]]
|[[Chips Dubbo]]{{Ref/Reuse|theark}}
|Survived
|-
|[[Gunnery Sergeant]]
|[[Marcus Stacker]]{{Ref/Reuse|theark}}
|Survived
|}
===Units===
====Ground forces====
*[[UNSC Navy]]
*[[UNSC Marine Corps]]
**[[S4/BLCE/1/7]]
**[[S4/BRT/1/7]]
***[[Alpha Company, S4/BRT/1/7|Alpha Company]]
***[[Charlie Company, S4/BRT/1/7|Charlie Company]]
**[[Orbital Drop Shock Trooper]]s
***[[105th Shock Troops Division|105th ODST Division]]
****[[7th Shock Troops Battalion]]{{Ref/Reuse|theark}}
***[[11th Marine Force Reconnaissance/ODST|11th MFR/ODST]]{{Ref/Reuse|Blind Faith}}
====Naval forces====
*[[UNSC Home Fleet|Home Fleet]]
**[[Seventh Fleet]]
***[[Battle Group Victory]]

===Artificial intelligence===
{{Main|Artificial intelligence}}
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
|[[Cortana]]
|Survived, listed as MIA
|}

===Covenant separatists===
===Naval assets===
====Starships====
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Tactical grouping
! Class
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
| rowspan="2" |[[Fleet of Retribution]]
| {{Class|CAS|assault carrier}}
|''[[Shadow of Intent]]''{{Ref/Reuse|theark}}
|Survived
|-
| {{Class|CCS|battlecruiser}}
|''[[Pious Inquisitor]]''{{Ref/Book|Id=EVG|EVG|Page=124}}
|Survived
|}
====Military personnel====
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Branch
! Rank
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
| rowspan="4" |Unknown
|[[Fleetmaster]]
|[[Rtas 'Vadum]]{{Ref/Reuse|theark}}
|Survived
|-
|[[Arbiter]]
|[[Thel 'Vadam]]{{Ref/Reuse|theark}}
|Survived
|-
| rowspan="2" |[[Special Operations Sangheili|Special Operations]]
|[[Usze 'Taham]]{{Ref/Site|Id=Coop|D=14|M=11|Y=2014|URL=http://halo.bungie.net/News/content.aspx?type=topnews&link=thesoundofsack|Site=bungie.net|Page=The Tru7h About Co-Op in Halo 3}}
|Survived
|-
|[[N'tho 'Sraom]]{{Ref/Reuse|Coop}}
|Survived
|}
===Units===
====Ground forces====
*[[Special Warfare Group|Fleet of Retribution Special Warfare Group]]
====Naval forces====
*[[Fleet of Retribution]]
**One [[battle group]]{{Ref/NoteReuse|composition}}
{{col-2}}

===Covenant===
===Naval assets===
====Starships====
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Tactical grouping
! Class
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
| rowspan="3" |[[Truth's fleet]]
| [[Forerunner]] [[keyship]]
|''[[Anodyne Spirit]]''
|Survived, assumed destroyed
|-
| {{Class|ORS|heavy cruiser}}
|''[[Foebane|Gathering of Praise]]''{{Ref/Reuse|loot5}}{{Ref/Reuse|envoy}}
|Escaped
|-
| [[Covenant frigate]]
|''[[Twilight Compunction]]''{{Ref/Reuse|loot5}}
|Destroyed
|}

====Military personnel====
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Branch
! Rank
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
| rowspan="2" |Unknown
|[[Shipmaster]]
|[[Hekabe]]
|Escaped
|-
|[[Jiralhanae Chieftain|Chieftain]]
|[[Cethegus]]
|KIA
|}

====Non-combatants====
{| class="wikitable sortable " style="width: 75%;" cellspacing="1" cellpadding="1" border="0"
|-
! Branch
! Rank
! Name
! Status<!--This refers to their status after the battle, not their overall status-->
|-
|[[High Council]]
|[[Hierarchs|Hierach]]
|[[Prophet of Truth]]
|KIA
|}

===Units===
====Naval forces====
*[[Truth's fleet]]†
**[[Hekabe's clan]]

{{col-end}}

==Gallery==
<gallery>
File:H3 SpaceBattle Concept.jpg|Concept art of the [[space warfare|space battle]] above Installation 00.
File:H3 Ark SentinelsVsCovenant.png|Covenant infantry and Shade turrets attacking Aggressor Sentinels.
File:H3 CethegusCharging.png|John-117 fires at Cethegus at the Cartographer.
File:Cool odsts.jpg|ODSTs attacking a War Chieftain and an Anti-Air Wraith.
File:Anti-Anti-Air.jpg|An Anti-Air Wraith fires upon an AV-14 Hornet and a Pelican.
File:H3 Brute Pack.png|A War Chieftain leading his Jiralhanae pack in defense of a barrier tower.
File:H3 BarrierTowerBattle.png|John-117, Thel 'Vadam, and Sangheili fighting a Jiralhanae pack.
File:H3 TheCovenant CitadelDogfight.png|Hornets and Banshees fighting above the Citadel.
File:H3 Scorpion firing at a Scarab.jpg|A Scorpion charges at a Scarab at the Citadel.
File:H3-JohnFlamethrower.jpg|John-117 fighting a Flood combat form inside ''High Charity''.
File:3Way2-large.jpg|John-117 and Thel 'Vadam come across Sentinels fighting Flood combat forms on Installation 08.
File:H3 Installation 08 blowing up.jpg|John-117 and 'Vadam escape Installation 08 on a Warthog.
</gallery>

==List of appearances==
*''[[Halo: First Strike]]''
**''[[Petra]]'' {{Mo}}
*''[[Halo 3]]'' {{1st}}
*''[[Halo Legends]]''
**''[[Origins]]''
*''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''
**''[[From the Office of Dr. William Arthur Iqbal]]'' {{Mo}}
*''[[Halo: Broken Circle]]'' {{Im}}
*''[[Halo: Hunters in the Dark]]'' {{Mo}}
*''[[Halo Mythos: A Guide to the Story of Halo]]'' {{Mo}}
*''[[Halo: Tales from Slipspace]]''
**''[[Dominion Splinter]]'' {{C|Flashback only}}
*''[[Halo Wars 2]]'' {{Mo}}
*''[[Halo: Envoy]]'' {{Mo}}
*''[[Halo: Legacy of Onyx]]'' {{Im}}
*''[[Halo: Bad Blood]]'' {{Mo}}
*''[[Halo: Shadows of Reach]]'' {{Im}}
**''[[Sacrifice]]'' {{Mo}}
*''[[Halo: Divine Wind]]'' {{Mo}}

==Notes==
{{Ref/Notes}}

==Sources==
{{Ref/Sources}}

{{Engagements in the Battle of Installation 00}}
{{Human-Covenant War}}
{{DEFAULTSORT:Installation 00}}
[[Category:UNSC Victories]]
[[Category:Battle of Installation 00| ]]
[[Category:Engagements in the Battle of Installation 00| ]]