Editing 2552

{{Status|Canon}}
{{References}}
{{Infobox/Timeline/CE
|image=File:H3 CitadelBattle.jpg|300px
|caption=The Covenant's final stand during the [[Battle of the Citadel|last battle]] of the war.
|other=
}}
'''2552''' was a year in the 2550s in the 26th century. It was the ultimate year of the [[Human-Covenant War]], during which the [[human]]s of the [[United Nations Space Command]] nearly saw utter defeat and extinction, though the tide turned, and with significant help from the [[Sangheili]], they managed to win the war. The [[Covenant]] were at the peak of their power and reach in 2552, with [[Siege of the Inner Colonies|major assaults on the human]] [[Inner Colonies]] and an invasion followed by a [[Battle of Earth|prolonged engagement]] on their home [[planet]], [[Earth]].<ref>'''[[Halo 2]]''', campaign level ''[[Cairo Station]]''</ref><ref>'''[[Halo: Ghosts of Onyx]]'''</ref><ref>'''[[Halo 3]]''', campaign level ''[[The Storm]]''</ref> During the [[Battle of Installation 04|battle]] at [[Installation 04]], the galaxy found its first large outbreak of the [[Flood]] threat in over a hundred thousand years.<ref>'''[[Halo: Combat Evolved]]''', campaign level ''[[343 Guilty Spark (level)|343 Guilty Spark]]''</ref><ref>'''Halo: Combat Evolved''', campaign level ''[[The Library]]''</ref> Over one month later, an even larger outbreak occurred at [[Installation 05]].<ref>'''Halo 2''', campaign level ''[[Sacred Icon]]''</ref>

The war finally drew to a close at [[Installation 00]], known more commonly as the Ark, with the humans and Sangheili attempting to kill the High [[Prophet of Truth]], before he could activate the remaining Halo installations.<ref>'''Halo 3''', campaign level ''[[The Ark (level)|The Ark]]''</ref><ref>'''Halo 3''', level ''[[The Covenant (level)|The Covenant]]''</ref> The alliance was successful in their mission against the Covenant and ended the 27 year long war.

==Events==
===Before June===
*The [[Battle of Beta Eridani]] takes place when the [[Fleet of Valiant Prudence]] invades the system. The UNSC is defeated and [[Rho 'Barutamee]] takes control of several Forerunner artifacts that lead him to [[Epsilon Eridani system|another system]].

===January===
'''January 8'''
*A team of [[ODST]]'s (Including [[Kojo Agu]] and [[Taylor H. Miles]]) descend onto [[Ariel]] (a small science colony) in response to a distress call on the planet in [[Operation: FIRESIDE]].<ref>[[Halo: Helljumper Issue 1]] page 3 "''UNSC Operation 2552-JA-8 Codename: Fireside''"</ref>

===February===
'''February'''
*[[Insurrectionist]]s on [[Harmony]] disable the planet's primary [[communications relay]] and steal two drydocked [[freighter]]s.<ref name="NobleActual">'''[[Halo: Reach]]''', campaign level ''[[Noble Actual]]''</ref>

===March===
'''March 9'''
*An entry is recorded in a UNSC Archive regarding a UNSC Excavation site headed by [[BXR Mining Corporation]] being bombarded by the Covenant. The miners managing to get the ore being mined to the surface before the mine totally collapsed.{{Ref/Generic|Id=Lightbringers|Heading=[[Become]]|Subheading=[[UNSC Archives]]|Detail=[[Lightbringers]]}}

===April===
'''April 22'''
*[[Battle of Fumirole]]: [[Noble Team]] member [[Thom-A293]] destroys a {{Pattern|Ket|battlecruiser}} but kills himself in the process, and [[Catherine-B320]] loses her arm. She subsequently receives a [[artificial limb|robotic prosthetic]].
'''Unknown Date'''
*The {{UNSCShip|Iroquois}} finishes construction.<ref name="Reach139">'''Halo: The Fall of Reach''', ''page 139''</ref>

===May===
'''May 10'''
*[[SPARTAN-B312]] takes part in a [[Mamore insurrections#2552|counter-insurgency operation]] on [[Mamore]]. The Spartan's skills as a [[FSS-1000 Sabre|Sabre]] pilot are exhibited during the op, prompting [[Colonel]] [[Urban Holland]] to have him transferred to Noble Team.
'''May 14 through May 19'''
*UNSC forces in the [[Earth Defense Coordination Zone]] are placed at maximum readiness levels and all warships with [[MAC|magnetic accelerator cannon]]s are self-deployed or towed to rally points. ''[[Cairo Station (station)|Cairo Station]]'' is established as flag headquarters.{{Ref/Reuse|lootcrate2}}
'''May 15'''
*[[Kalmiya]] informs Dr. Halsey about several documents she watched in Vice Admiral [[Michael Stanforth]]'s Beta-5 server which ranges from service order transfers of existing Spartan-IIs to highly classified non-Spartan-II detachments.{{Ref/Book|Id=DHD051552|Dr. Halsey's personal journal|Section=May 15, 2552}}
'''May 24'''
*[[Smart AI]] [[Gabriela]] is activated.{{Ref/Book|Id=Enc22P108|Enc22|Page=108}}

===July===
'''Unknown date'''
*The [[Battle of New Jerusalem]] takes place sometime this month or the [[2552#August|next]].<ref name="Halo page 153">'''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''', "[[Dirt]]", ''page 153''</ref> The [[26th Marine Expeditionary Force]] is nearly wiped out, leaving [[Private First Class]] [[Jonathan Doherty]] as one of the few survivors.<ref name="bungie.net">[http://halo.bungie.net/projects/odst/guide.aspx '''Bungie.net''': ''Halo 3: ODST Field Guide'']</ref>  

'''After July 5'''
*[[Gabriel Thorne]] single-handedly saves his entire platoon in the Battle of Criterion.

'''July 17'''
*The Slipspace monitoring probes from [[Remote scanning outpost|Remote Scanning Station]] ''[[Archimedes]]'' at the edge of the [[Sigma Octanus system]] encounter the [[Covenant]] ships sent to attack [[Sigma Octanus IV]].
*The {{UNSCShip|Iroquois}} is tasked with patrolling the Sigma Octanus star system.
*The [[Battle of Sigma Octanus IV]] begins.

'''July 18'''
*The UNSC win a victory during the battle at Sigma Octanus IV. [[Commander]] [[Jacob Keyes]], of the {{UNSCShip|Iroquois}}, plays a critical role in this success when he devises the [[Keyes Loop]] maneuver. Keyes is subsequently promoted to [[Captain (Navy)|Captain]] by [[Vice Admiral]] [[Michael Stanforth]]. Unknown to the UNSC, the Covenant place a [[spy probe|tracker]] on the hull of the ''Iroquois''. The importance of [[Reach]] to the UNSC is revealed to the Covenant when the ''Iroquois'' returns to that world. 
*Vice Admiral Stanforth messages the director of the Office of Naval Intelligence, [[Margaret Parangosky|Admiral Margaret Parangosky]], with information on the battle at Sigma Octanus IV, as well as the ongoing progress of [[Operation: BRAVADO]].<ref>[https://www.halowaypoint.com/en-us/universe/oni-files/reach-data-drops ''Data Drop Two (Reach Data Drops)'']</ref>

'''July 23'''
*The Covenant deploy the [[Fleet of Valiant Prudence]] to sever Reach's out-system communications and search for Forerunner artifacts. This is the first stage of the Covenant's [[Fall of Reach|invasion of the planet]].
*Noble Team finds and stops a pair of Insurrectionist SCI combatants attempting to hijack a supply transport.{{Ref/Reuse|NobleActual}}
*Fireteam [[3 Charlie]], along with other special warfare fireteams under command of Colonel Holland, are sent to investigate the areas around [[Longhorn Valley]] and [[Visegrád]] after contact with the [[Visegrád Relay|comms relay]] in Visegrád is lost.

'''July 24'''
*Two months after the death of Thom-A293, SPARTAN-B312 joins Noble Team as Noble Six.
*Noble Team is sent by Colonel Holland on a mission to investigate the downed Visegrád Relay.{{Ref/Reuse|NobleActual}}
*Noble Team discovers the Covenant's presence on Reach for the first time at Visegrád Relay. Planetary directive [[WINTER CONTINGENCY (protocol)|WINTER CONTINGENCY]] is declared.

'''July 26'''
*[[SWORD Base]], an ONI research facility on Reach, comes under attack by an {{Pattern|Ceudar|heavy corvette}}. The [[UNSC Army]] with the help of Noble Team successfully repel the attack and the corvette is destroyed by orbital support.

===August===
'''Unknown date'''
*After discovering Reach, the Covenant move on to glass the other planets in the system, including [[Tribute]], resulting in the prolonged [[Battle of Tribute]].
*During the Battle of Tribute, [[SPARTAN-II]] [[Team Black]] is sent to [[Verge]] to destroy a Covenant [[Beacon]] supplying [[Helium|helium-3]] to the ships laying siege on Tribute. The team successfully destroys the beacon.<ref>'''[[Halo: Evolutions - Essential Tales of the Halo Universe]]''' - ''[[Blunt Instruments]]''</ref>
*After the mission on Verge, [[Vice Admiral]] [[Alexander Reaves]] assigns Fireteam Black to [[Operation: BLOWBACK]], a covert mission in Covenant-occupied space. [[UNSC Long Time Coming|Their ship]], as well as a [[Clarity of Faith|Covenant carrier]], crash-land on an [[Unnamed Moon|unknown moon]], igniting the [[Battle of Line Installation 1-4]].
*[[Margaret-053]] is captured by [[Forerunner]] [[Gatherer]]s. Team Black and the Covenant forces on the moon enter into a reluctant alliance to rescue the Spartan.
*Fireteam Black encounters the Forerunner monitor [[686 Ebullient Prism]] en route to rescuing Margaret-053. The monitor briefly causes rifts between the team to prevent them from rescuing their comrade. Margaret, however, escapes anyway, aided by [[Reff 'Talamee]], and the rest of Team Black stop fighting amongst themselves.
*Team Black manages to enter the control room of Line Installation 1–4, eventually destroying 686 Ebullient Prism with the installation's main gun; they also succeed in destroying the entire Covenant fleet.
*[[Beta Gabriel]] is captured by a pack of [[Jiralhanae]] under the command of [[Chieftain]] [[Parabum]]. A majority of the sparse human population is either taken prisoner or killed, including ONI agent [[Connor Brien]], who had been sent on a mission to study the Brutes. A recon force of [[ODST]]s are sent in to neutralize the Brutes, and are successful in doing so.
* The [[Raid on Mount Haven]] takes place.<ref>[https://www.halowaypoint.com/en-us/universe/characters/rookie '''Halo Waypoint''', ''Rookie'']</ref> The {{UNSCShip|Chares}} deploys ODSTs in a snatch-and-grab mission to secure the transport of a Forerunner artifact, but after a chain of events involving a group of rogue ODSTs attempting to steal [[gold]] from a bank vault, [[Gage Yevgenny|a wounded ODST]] manages to halt their operations with a [[Shiva]] nuclear warhead.<ref>'''Halo: Evolutions - Essential Tales of the Halo Universe''' - ''[[Dirt]]''</ref>  Eventually, the surviving civilians and UNSC forces fall back to Earth, having been informed Reach was just attacked.{{Ref/Reuse|Halo page 153}}

'''August 1'''
*'''0250 Hours:''' Vice Admiral Michael Stanforth and half of [[Battle Group Leviathan]] return to Epsilon Eridani system. In a message send to Parangosky, Stanforth expresses his concerns about sacrificing Reach for the sake of Operation: RED FLAG.{{Ref/Generic|Id=DD4|[[Data Drop]]|Subheading=[[Data Drop/DDR4|DDR4]]|Detail=[[:File:DDR-A340021-0250-08-01-52.pdf|DDR-A340021-0250-08-01-52.pdf]]}}

'''August 3'''
*Dr. Halsey decides to split Cortana in two halves, with her IEP translation routines analyzing the Forerunner structure under SWORD Base and the other half continuing with John and Blue Team in preparation for Operation: RED FLAG.<ref name="journal">'''[[Halo: Reach]]''', ''[[Dr. Halsey's personal journal]]''</ref>

'''August 5'''
*Cortana's split is a success.{{Ref/Reuse|journal}}

'''Early August (sometime from the 6th to the 12th)'''
*The {{UNSCShip|Apocalypso}} crashes in lunar orbit, a [[slipspace anomaly]] knocking out communications within the Solar System for [[seven]] seconds.

'''August 11'''
*SPARTAN-B312 and Jun-A266 engage in a recon mission on Covenant forces in the colloquially named "Dark Zone", a Covenant-occupied region in the Viery Territory. The two Spartans discover a Covenant invasion force and a landing zone. Kat-B320 receives the visual and tells them to retreat so they will be prepared for the next day.<ref>'''Halo: Reach''', campaign level ''[[Nightfall]]''</ref>

'''August 12'''
*Battle Group Leviathan and the ''Iroquois'' arrives at Reach for emergency refit and repairs.{{Ref/Reuse|journal}} While the battle group was being repaired, Stanforth and Keyes arrived at [[Camp Hathcock]] in the [[Highland Mountains]] on Reach for debriefing. Shortly after, they returned to their respective vessels within the battle group.<ref>'''Halo: The Fall of Reach''', ''page 252'' (2010)</ref>
*Around this time, Stanforth engages a small group from the [[Fleet of Valiant Prudence]] dispatched to retrieve a [[Site 17 artifact|Forerunner artifact]] from ONI's [[Teller Station]] in the Epsilon Eridani [[Oort cloud]]; though he sends reinforcements to successfully cover the station's evacuation, he loses irreplaceable personnel and ships in the process.<ref name="fb4">'''Halo: Fleet Battles''', ''Scenario Four: Run!''</ref><ref name="fb5">'''Halo: Fleet Battles''', ''Scenario Five: Into The Fire''</ref>
*Halsey reviews the upgrades to the new MJOLNIR Mark V.{{Ref/Reuse|journal}}
*[[John-117]] and [[Harland|Corporal Harland]] are debriefed by [[ONI]] at [[Camp Hathcock]], Reach, on the events on [[Côte d'Azur]] during the Battle of Sigma Octanus IV.
*[[Battle at Szurdok Ridge]]: UNSC forces assault an amassing Covenant invasion force in the [[Viery Territory]] on Reach, managing to destroy two [[Cheru-pattern Tyrant|AA plasma cannons]] and a [[Spire One|Covenant spire]]. However, the cloaked [[Sh'wada-pattern supercarrier|supercarrier]] ''[[Long Night of Solace]]'' reveals itself and destroys the frigate {{UNSCShip|Grafton}}, which had been providing air support.<ref>'''Halo: Reach''', campaign level ''[[Tip of the Spear]]''</ref>

'''August 13'''
*60% of the [[Epsilon Eridani Fleet]] is recalled to Reach, destined to arrive within the next 48 hours.<ref name="lnos">'''Halo: Reach''', campaign level ''[[Long Night of Solace (level)|Long Night of Solace]]''</ref>

'''August 14'''
*[[Operation: UPPER CUT]] and [[Operation: LEFT JAB]] are initiated, as Noble Team retakes the [[Sabre Program Launch/Research Range]] at [[Farkas Lake]] and joins the battle in orbit, eventually capturing the Covenant corvette ''[[Ardent Prayer]]'' and using it to deliver the {{UNSCShip|Savannah}}'s [[Shaw-Fujikawa Translight Engine]], used as a makeshift bomb, to the ''Long Night of Solace'' . The ''Solace ''is destroyed at the cost of [[Jorge-052]], who sacrifices himself to detonate the drive manually. Moments after the carrier's destruction, a large Covenant fleet sent by the [[Ministry of Resolution]] enters in-system.{{Ref/Reuse|lnos}}
*Following the destruction of the ''Solace'', [[Kantar 'Utaralee]], now acting [[fleetmaster]] of the [[Fleet of Valiant Prudence]], leads what little ships he has left in a last-ditch effort to recover Teller Station's [[Site 17 artifact|artifact]], now residing in a UNSC [[space station]] orbiting the [[moon]] of [[Turul]].<ref name="fb">'''[[Halo: Fleet Battles]]''', ''Scenario Eight: Rally Point Zulu''</ref> 

'''August 17'''
*[[Smart AI]] [[Black-Box]] is created from [[Graham Alban|a human brain]] donor to be the personal AI companion for Admiral Margaret Parangosky and activated on [[Mars]].<ref>[https://www.halowaypoint.com/en-us/universe/characters/blackbox '''Halo Waypoint''': ''Black-Box'']</ref>{{Ref/Book|Id=Enc22P109|Enc22|Page=109}}

'''August 18'''
*The [[Siege of New Alexandria]] begins as the Covenant lay siege to the [[city]] of [[New Alexandria (location)|New Alexandria]].

'''August 23'''
*Noble Six arrives in New Alexandria and helps evacuate civilians from the city. He also manages to severely damage one of the corvettes laying siege to the city by use of an AA missile battery. Noble Six eventually meets up with the rest of Noble Team, and the Covenant begin glassing the city. As Noble Team is on their way to a fallout shelter under the [[Olympic Tower]], Kat-B320 is killed by sniper fire.<ref name="new alexandria">'''Halo: Reach''', campaign level ''[[New Alexandria]]''</ref>

'''August 24'''
*Dr. Halsey examines the rock recovered by Blue Team during Operation: OCEAN BREAKER on Sigma Octanus IV.{{Ref/Reuse|journal}}

'''August 25'''
*Dr. Halsey and [[Cortana]] choose the {{UNSCShip|Pillar of Autumn}}, with Jacob Keyes as its commander, for a secret mission Halsey is planning.

'''August 26'''
*The remainder of Noble Team is evacuated from the destroyed New Alexandria via a Pelican.{{Ref/Reuse|new alexandria}}

'''August 27'''
*All available SPARTAN-IIs gather at the [[Reach FLEETCOM Military Complex|FLEETCOM Military Complex]] on Reach, where they learn of their [[Operation: RED FLAG|next mission]]: to acquire a Covenant vessel, navigate to the Covenant home world, and return with captured Covenant [[Hierarchs|leadership]].

'''August 29'''
*John-117 receives a [[SPARTAN neural interface|neural interface]] upgrade, the second generation of [[MJOLNIR Powered Assault Armor/Mark V|MJOLNIR Mark V armor]], and is introduced to Cortana.
*Noble Team is ordered to destroy Sword Base in a torch-and-burn op. During the operation, Noble Team makes their way inside Sword Base where they encounter Dr. Halsey, who asks them to protect her lab. Noble Team is then given direct orders to escort a fragment of Cortana holding crucial data from the [[Babd Catha Forerunner complex]] to the ''Pillar of Autumn''. Halsey is then escorted back to CASTLE base by [[Jun-A266]].

'''August 30'''
[[File:Fall of Reach 1.jpg|300px|thumb|[[Fall of Reach|Reach falls]] to the Covenant.]]
*Cortana has ONI [[Colonel]] [[James Ackerson]] illicitly transferred to the front. This is her revenge for his attempts to eliminate both her and John-117.
*[[First Lieutenant]] [[Jake Chapman]], along with most of [[Charlie Company]] is killed during the Fall of Reach.
*The Covenant, despite sustaining heavy losses, wins a crushing victory at the Fall of Reach. Many of the remaining SPARTAN-IIs are killed.
*The surviving [[SPARTAN-IIs]] on Reach are separated into two groups. One recovers [[Danforth Whitcomb|Vice Admiral Whitcomb]] and goes into hiding at [[Camp Independence]]. The others are admitted into [[CASTLE Base]] by Dr. Halsey and receive parts of the [[MJOLNIR]] Mark V upgrade and new weapons.
*Dr. Halsey learns of [[Colonel Ackerson]]'s [[SPARTAN-III Program|mysterious plans]] that seem to involve "her" [[Spartans]].
*The three surviving members of [[Noble Team]] arrive at Asźod; [[Carter-A259]]'s Pelican becomes too badly damaged to continue carrying them all, so Noble Six and [[Emile-A239]] deploy to the ground. 
*[[Battle of Asźod]]: The Covenant forces throughout [[Asźod]] attempt to stop Noble Six and Emile from reaching the ''[[UNSC Pillar of Autumn|Pillar of Autumn]]'', going so far as to deploy [[Deutoros-pattern Scarab|Scarabs]] against them. Carter sacrifices himself when he steers his damaged Pelican into a Scarab, destroying it. Emile and Six proceed to push towards the [[Asźod ship breaking yards|ship breaking yards]] and rendezvous with the scant UNSC forces still attempting to defend the facility. After clearing most of the facility, Six, Emile, and several Trooper squads meet up with Captain Jacob Keyes, successfully delivering the fragment of Cortana. However, Emile is killed by a [[Sangheili Zealot]]. 
*SPARTAN-B312 destroys a ''Ket''-pattern battlecruiser with a [[15cm Mark/2488 1.1GJ MAC|mass driver]] to allow the ''Pillar of Autumn'' to escape Reach. The Spartan is killed by Sangheili soon after. The ''Autumn'' jumps away from the system, with Cortana using Forerunner navigation data from the [[Sigma Octanus IV artifact]] as well as the Babd Catha Forerunner complex.

===September===
'''Unknown date'''
*The planet [[Coral]] is reported glassed by the Covenant.

'''September 4'''
*[[Lieutenant Wagner]] returns to Earth and reports on the evident destruction of Reach to the [[UNSC Security Council]] ([[Colonel James Ackerson]], [[Fleet Admiral]] [[Terrence Hood]], and [[Major General]] [[Nicolas Strauss]]) at [[HIGHCOM Facility Bravo-6]] in Sydney, [[Australia]].  Hood determines that the location of Earth is compromised and decides that all [[ONI]] theatres of operation must be relocated. The Security Council also begins planning for the final defense of Earth.
*ONI launches an investigation of a [[SecNet]] conversation between [[Sergeant]]s [[Joseph M. Poteet]] (Username: TRIGTECH) and [[Alasdair R. Schicker]] (Username: GLancer) to discover whether they might have accidentally leaked the location of Reach to the Covenant.<ref>'''Halo: The Fall of Reach''' (2010) - ''Adjunct''</ref>

'''September 5'''
*[[UNSC]] fleet actions in the [[Reach Defense Coordination Zone]] conclude.{{Ref/Reuse|lootcrate2}}
*All remaining [[UNSC Navy|naval]] forces are consolidated into a single command grouping: the [[UNSC Home Fleet]]. 
*Fleet Admiral [[Joseph Harper]] of the [[Fifth Fleet]] is appointed senior flag officer of the Home Fleet and given primary administrative and tasking authority over all assets in the [[Sol system]] under emergency directives authorized by [[UNSC High Command]] and approved by the [[UEG Security Council]].{{Ref/Reuse|lootcrate2}}

'''September 14'''
*A new set of [[orbital defense platform]]s over Earth are scheduled to come online.<ref>'''Halo: First Strike''', ''page 104''</ref>

'''September 18'''
*'''Around 2200 hours ship time''': Captain Keyes and other key crew wake up on the {{UNSCShip|Pillar of Autumn}}, and check the status of the ship.<ref>'''Halo: The Fall of Reach Epilogue''', ''page 377(Definitive Edition)''</ref>

'''September 19'''
*Captain Keyes and crew make it to the bridge of the ''Pillar of Autumn'' and ask Cortana to shut down all systems before returning to normal space. The ''Pillar of Autumn'' then leaves slipspace, and glides around [[Basis]] into [[Threshold]]'s orbit, at which point Cortana detects a radio echo in the shadow of Threshold.
*'''0103 hours ship time''': The ''Pillar of Autumn'' cryo team prepare to wake John-117 under orders from Captain Keyes. Meanwhile, the Covenant [[Fleet of Particular Justice]] prepare to attack the ''Pillar of Autumn''.<ref>'''Halo: The Flood''', ''Prologue''</ref>
*The [[Battle of Installation 04]] begins.
*'''0120 hours ship time''': Keyes learns of the Covenant presence in the system and decides to wake the whole crew out of cryo.<ref>'''[[Halo: Combat Evolved]]''', campaign level ''[[The Pillar of Autumn (Halo: Combat Evolved level)|The Pillar of Autumn]] opening cutscene''</ref>
*'''0127 hours ship time''': The Fleet of Particular Justice finally strike the ''Pillar of Autumn''. John-117 is also woken from cryo sleep around this time and tasked with preventing Cortana's capture by the Covenant. John-117 and Cortana escape the ''Pillar of Autumn'' aboard a [[Class-3 Enclosed Heavy Lifeboat, Controlled|Bumblebee escape pod]], which later crashes on the ring.<ref>'''Halo: The Flood''', ''Chapter 1''</ref>
*The Pillar of Autumn is forced to crash land on the ring. A significant portion of its crew survives to continue the fight on the ground.
*Captain Keyes and the others in his escape pod are captured by the Covenant. Only Keyes escapes summary execution, and is taken to the {{Pattern|Ket|battlecruiser|}} ''[[Truth and Reconciliation]]'' for interrogation. 
*A large group of ODSTs and survivors, under the command of [[Major]] [[Antonio Silva]], (who assumed command of ''Autumn'' 's surviving crew after Captain Keyes' capture by the Covenant) establish [[Alpha Base (Installation 04)|Alpha Base]], which serves as the main tactical firebase for the survivors and as a staging point for any future Covenant attacks. 
[[File:SC new.png|200px|thumb|John-117 leading Marines on Installation 04.]]
*John-117 leads a [[UNSC Marine Corps|Marine]] force to board the ''Truth and Reconciliation''. They recover Keyes and escape aboard a [[Dextro Xur-pattern Spirit|Covenant dropship]].

'''September 20'''
*Keyes orders John-117 to find the "[[Silent Cartographer]]", a map room that will reveal the location of the [[Control Room]]. Keyes leaves to lead an assault on a Covenant weapons cache.
*Having found the map room and the pertinent information, Cortana directs a [[Echo 419|Pelican]] to take them to the area where the ring's Control Room is. Upon reaching the Control Room, Cortana transfers to the Control Room's computer and directs John-117 to stop Keyes from accessing the 'weapons cache', in reality a [[Forerunner]] [[Flood containment facility]].
*Before transporting the Chief to the supposed weapons cache, [[Carol Rawley]] records a mission report detailing their underground insertion near the Control Room. This report is entered into the UNSC Archives.<ref>'''[[Halo Infinite: Memory Agent]]''', ''[[Chapter 3: We Deliver]]''</ref>
*John-117, without Cortana, enters the supposed weapons cache but is unable to locate Keyes. Instead, he discovers [[the Flood]] and is forced to retreat. He links up with marines and takes command of the surviving members of Keyes' team and together they fight their way to the extraction point. However, the Spartan is conscripted by [[343 Guilty Spark]] and [[Slipspace translocation|teleported]] away before he can be evacuated with the surviving members.
*Major Silva and the others under his command abandon Alpha Base after discovering a large Flood infestation beneath the base. They then learn that the ''Truth and Reconciliation'' has been abandoned and lead a strike force to capture the ship. 
*The Flood succeed in capturing the Covenant dropship ''[[Brilliant Gift]]'', and use it to crash-land on board the Covenant ship ''[[Infinite Succor]]'', in orbit above Installation 04, with the intent to spread itself to the rest of the Fleet of Particular Justice. This is avoided when [[Special Operations Commander]] [[Rtas 'Vadumee]] sets the ''Infinite Succor'' on a crash-course vector for the system's star, [[Soell]]. Rtas 'Vadumee is the only survivor.
*The [[SPARTAN-IV program]] enters development under the oversight of Admiral [[Margaret Parangosky]], [[CINCONI]]. The project's existence is kept secret from both Dr. Catherine Halsey and Colonel James Ackerson, the respective creators of the SPARTAN-II and SPARTAN-III programs.<ref>[https://www.halowaypoint.com/en-us/universe/factions/spartans '''Halo Waypoint''' - ''Spartans'']</ref>

'''September 21'''
*The Monitor takes John-117 to the ring's [[Library]] to retrieve the [[Activation Index]], a device needed to activate the ring's primary weapon. Having retrieved the Index, the Monitor teleports the Spartan back to the Control Room where an irate Cortana confiscates the Index and prevents the ring from firing. John-117 and Cortana flee a now-hostile 343 Guilty Spark and [[Sentinel]]s.
*To forestall the ring from being activated manually, John-117 disables the ring's three [[phase pulse generator]]s. This is to buy time to destroy the ring by activating the auto-destruct on the ''Pillar of Autumn''. Only Keyes' [[command neural interface]] can activate the ship's self-destruct, and John-117 embarks once more to rescue the captain.
*The failed attempt to activate Alpha Halo results in the first [[Onyx Sentinel]]s appearing.{{Ref/Novel|GoO|Page=175|Quote=Halsey: That timing coincides with the activation of an alien weapon world - before John thankfully destroyed it. It is no coincidence that the Sentinels appeared then. It must be part of a larger Forerunner plan.}}

'''September 22'''
*Cortana teleports John-117 to the now Flood-overrun ''Truth and Reconciliation'' where Jacob Keyes is being held. Alas, the pair arrives too late to save Keyes, who has been merged into a [[proto-Gravemind]]. John-117 retrieves the neural interface by punching in the former-captain's head. Cortana downloads the necessary codes, and the duo returns to the ''Pillar of Autumn'' on a captured [[Banshee]].
*Major Silva's forces arrive at the ''Truth and Reconciliation'' and take over the ship through a combined surprise assault on the vessel's hangar bay and gravity lift. They also manage to capture the cruiser's prophet, the [[Prophet of Stewardship]]. After capturing the cruiser, Major Silva intends to fly the ship back to Earth in order to be recognized as the hero of the Battle of Installation 04; this acts a both a huge violation of the Cole Protocol and risks spreading the Flood. First Lieutenant [[Melissa McKay]] realizes this, so, in a snap-decision, she severs the primary optical fiber cable that linked controls from the bridge to engineering with a fragmentation grenade, thereby causing the cruiser to lose control and crash onto the surface of Halo.
*343 Guilty Spark overrides the auto-destruct sequence, forcing John-117 to manually destabilize the ship's still-functioning fusion cores. John-117 and Cortana then escape the resulting explosion and the fragmentation of the ring aboard a Longsword.
*[[Avery J. Johnson|Staff Sergeant Johnson]], [[Lieutenant Haverson]], [[Warrant Officer Polaski]], and [[Corporal Locklear]] also escape the destruction of the ring aboard a Pelican.
*In the course of the ring's destruction, [[Alpha Shard|a fragment]] of Installation 04 enters slipspace. This fragment later re-enters normal space in the vicinity of a red giant star.<ref name="wp shard">[https://www.halowaypoint.com/en-us/universe/locations/halo-ring-fragment '''Halo Waypoint - Universe''': ''Alpha Shard'']</ref>
*The Battle of Installation 04 ends. John-117 and Cortana rendezvous with Johnson's group in Installation 04's debris field. They also recover a set of [[cryo chamber]]s, one which contains [[Linda-058]].
*[[Skirmish over Threshold]]: As the [[Longsword]] and Pelican are not jump capable, the UNSC survivors assault and capture the Covenant flagship ''[[Ascendant Justice]]''. They then set course for Reach.
*[[Jersey Morelli]] confronts his mother about having an affair.

'''September 23'''
*The month's temporal anomaly is seemingly rectified by this date.
*After the destruction of Installation 04, [[Installation 00]] commences the [[Installation 08|construction of the replacement]] for Installation 04.

'''September 26'''
*ONI agent [[Jameson Locke]] compiles a target profile report concerning Supreme Commander Thel 'Vadamee, detailing 'Vadamee's personal history from the start of the Human-Covenant War to the glassing of Reach.<ref>'''[[Halo 2: Anniversary]]''', ''[[Terminal (Halo 2: Anniversary)|Terminals]]''</ref>

'''September 27'''
*Covenant glassing operations on [[Reach]] ends.{{Ref/Book|Id=Enc22|Enc22|Page=42-43}}

====September's anomaly====
After the recovery of a Forerunner device on Reach, the members of an organized resistance comprised of Spartans from Reach and survivors of the Battle of Installation 04 are in some sort of time anomaly, causing them not to be in the "correct timeline".<ref>'''Halo: First Strike'''</ref> What is known is that the events take place with the possession of the device after September 7.

[[File:Fight on Ascendant Justice.png|thumb|250px|John-117 and Marine survivors fighting on the ''Ascendant Justice''.]]
'''September 7'''
*The time/date record anomaly of Sept 23, 2552 most likely rejoins the correct timeline.
*Dr. Halsey and members of Red Team discover an [[Forerunner crystal|enigmatic shard]] in a [[Menachite Forerunner Complex|Forerunner installation]] below CASTLE Base. They are besieged by Covenant forces who seek to possess the shard.
*Dr. Halsey initiates [[Operation: WHITE GLOVE]], destroying CASTLE Base, thus preventing the Covenant forces above from capturing any UNSC or Forerunner technology. Halsey and members of [[Red Team]] are protected from the resulting detonation when they hide in the caves beneath the base.
*The remaining Spartans, [[Danforth Whitcomb|Admiral Whitcomb]], Dr. Halsey, [[Avery Junior Johnson|Sgt. Johnson]], [[Elias Haverson|Lieutenant Haverson]], Warrant Officer Polaski, and Corporal Locklear jump to Slipspace on board the Covenant/UNSC hybrid ship {{UNSCShip|Gettysburg}}-''Ascendant Justice'', and discover that the shard seems to have the ability to bend both space and time.

'''September 12'''
*The ''Gettysburg''/''Ascendant Justice'' arrives for refit and provisioning in the Eridanus system. 
*Vice Admiral Whitcomb secures a meeting with rebel leader Governor [[Jacob Jiles]], attempting to reason with him that the Covenant would most likely arrive to claim the Forerunner crystal. When several Covenant warships emerge from slipspace, Jiles agrees to help the UNSC forces. 
*Dr. Halsey sedates [[Kelly-087]], and absconds with her on Governor Jiles' personal ship, the [[Chiroptera-class subprowler|''Chiroptera''-class]] ''[[Beatrice]]''. Before she goes, she gives the Forerunner crystal to Corporal Locklear, with implicit instructions to destroy it. 
*A large Covenant fleet enters the Eridanus system, forcing the hand of Admiral Whitcomb; he pulls out and retreats, as does the ''Gettysburg''/''Ascendant Justice'', leaving the rebels to their doom. 
*Governor Jiles is killed and the [[Eridanus rebels]] are destroyed during the [[Massacre at Eridanus Secundus]]. Eridanus Secundus itself is destroyed by the Covenant.

'''September 13'''
*UNSC forces aboard the ''Gettysburg/Ascendant Justice'' win a crucial victory at the [[Operation: FIRST STRIKE|Battle of the ''Unyielding Hierophant'']]. [[SPARTAN-093]], Lieutenant Haverson of ONI and Vice Admiral Whitcomb are killed. The survivors, now aboard the singular {{UNSCShip|Gettysburg}} and with a captured Covenant slipspace drive, depart for Earth to warn of the impending Covenant invasion.

===October===
'''Unknown date'''
*An edict from the Office of the High Prophet of Truth orders that in the virtue of the Jiralhanae, all Sangheili posted with the [[Fleet of Profound Solitude]], the [[Fleet of Tranquil Composure]], and the [[Fleet of Inner Knowledge]] to be completely replaced by Jiralhanae. Each removed Sangheili to be assigned other duties. In celebration, all imprisoned or criminal Jiralhanae were released, rehabilitated, and pardoned.<ref>'''Halo Wars''': ''Halo Timeline''</ref>
*[[ODST]] [[Sarah Palmer]], the future commander of the [[SPARTAN-IV program|SPARTAN-IVs]] on {{UNSCShip|Infinity}}, rescues [[Admiral]] [[Kovalic]] and a vital AI from a planet under Covenant attack. Wounded in action, Palmer is sent to [[Lockhart medical station|''Lockhart'' medical facility]] to recover.<ref name="Initiation">'''Halo: Initiation''', ''Issue 1''</ref>

'''October 8'''
*After escaping from the Battle of Tribute, the freighter ''[[Floral Express]]'' discovers [[Installation 03]].<ref name="11hour">''[[Eleventh Hour reports]]''</ref>
*[[Admiral]] [[J. Garcia]] forwards Log 01–0089 to [[UNSC High Command]], which contains the preliminary reports of action during the [[Fall of Reach|Defense of Reach]].<ref name="lootcrate2">'''[[Halo Legendary Crate]]''', ''[[Halo Legendary Crate/Data Drops|Data Drop #2]]''</ref>

'''October 9'''
*Doctor [[O. Cheng]] forwards Log 01–0921, an intelligence report incorporating recent naval losses during the [[Fall of Reach]], to the [[UNSC Security Council]].{{Ref/Reuse|lootcrate2}}

'''October 10'''
*The [[UNSC Navy]]'s [[Third Fleet]], and specifically [[Battle Group Rhino]] loses the {{UNSCShip|Totem Lake}} in the [[Battle of October 10]].{{Ref/Reuse|lootcrate2}}

'''October 13'''
*On [[Argyre Planitia]], [[Mars]], gravitic and radiation anomalies are detected by UNSC scouting teams. After on-site search and assessment, cloaked remote sensors are discovered, and WIDEAWAKE cryptonym is triggered, but an stand-down order is issued by Fleet Admiral Joseph Harper after consulting with CINCONI Parangosky.{{Ref/Reuse|lootcrate2}}

'''October 17'''
*[[Captain]] [[W. Murray]] reports an after-action report of the [[Battle of October 10]] in the form of 83 files later termed Log 01–0991.{{Ref/Reuse|lootcrate2}}

'''October 19'''
*Aboard ''Cairo Station'', Sergeant Johnson is interrogated by Dr. [[Veronica Clayton]] of ONI in regards to the events surrounding [[Operation: First Strike]].<ref>'''[[Halo Legendary Crate]]''', ''[[Halo Legendary Crate/Data Drops|Data Drop #10]]''</ref>
*Cortana details the Battle of Installation 04 to ONI.{{Ref/Reuse|11hour}}
*During a routine seismic scan, [[Vergil]], a subroutine of [[New Mombasa]]'s [[Superintendent]] AI, discovers a [[Portal at Voi|seismic anomaly]] underneath the city. The report is accessed by [[Endesha|Dr. Daniel Endesha]], a scientist responsible for the management of the AI.<ref>''[[Sadie's Story]]''</ref>
*[[Staff Sergeant]] [[Malcolm Geffen]] forwards Log 01–1101, an intelligence report about the anomalies registered on Mars.{{Ref/Reuse|lootcrate2}}

'''October 20'''
[[File:H3ODST MombasaBattle Concept.jpg|200px|thumb|The Battle of Earth at Mombasa.]]
*John-117 is outfitted with the [[MJOLNIR Powered Assault Armor/Mark VI|MJOLNIR Mk. VI]] aboard ''[[Cairo Station (station)|Cairo Station]]''.
*'''1248 hours''': [[Io Station]] detects a possible Covenant sighting in the [[Sol system]] and contacts the [[UNSC Home Fleet]]. Cortana, on board the ''Cairo'', receives the message and briefs Lord Hood.{{Ref/Reuse|lootcrate2}}<ref>'''[[Halo 2]]''', level ''[[Cairo Station]]''</ref> 
*On [[High Charity]], [[Thel 'Vadam]]ee, the disgraced [[Supreme Commander]] of the [[Fleet of Particular Justice]], is deemed a heretic by the Covenant [[High Council]] and is sentenced to death for his failure to safeguard [[Installation 04]] one month prior.
*John-117 and Staff Sergeant (now promoted to Sergeant Major) Johnson are awarded the [[Colonial Cross]] at a ceremony aboard Cairo Station. Captain Keyes is awarded posthumously and the decoration is entrusted to his daughter, [[Miranda Keyes]].
*Instead of being executed, 'Vadamee is given the title of [[Arbiter]] by the High Prophets of Truth and Mercy, and sent to [[Threshold]] with Rtas 'Vadumee and [[Tartarus]] on [[Raid on the Threshold gas mine|a mission]] to eliminate a band of [[Sesa 'Refumee's heretic faction|heretics]] led by [[Sesa 'Refumee]]. Following 'Refumee's death, the group recovers [[343 Guilty Spark]].
*The [[High Prophet of Regret]]'s [[Fleet of Sacred Consecration|fleet]] eventually arrives at Earth, not expecting any human presence. The vastly outnumbered Covenant force attacks the UNSC Home Fleet without seeking support from other Covenant forces, precipitating the Battle for Earth.
*'''1412 hours''': Lord Hood and Fleet Admiral [[Joseph Harper|Harper]] coordinate Earth's orbital defense during the opening stages.
*'''1421 hours''': ''[[Malta Station]]'' and ''[[Athens Station]]'' are destroyed, clearing the way for the first attack wave.
*'''1450 hours''': John-117 foils a Covenant attempt to destroy the ''Cairo'' and instead uses the bomb to sabotage the ''[[Day of Jubilation]]'', one of Regret's only two assault carriers. 
*'''1459 hours''': Having successfully made it planetside, Regret's remaining carrier and flagship, ''[[Solemn Penance]]'', initiates a [[Battle of Mombasa|ground assault]] on New Mombasa. 
*John-117 is recovered by the {{UNSCShip|In Amber Clad}} and deploys to Mombasa in an attempt to capture the Prophet.
*The [[civilian]] populace begins to evacuate; Dr. Endesha's daughter [[Sadie Endesha|Sadie]] and former [[NMPD]] cop [[Mike Branley]] [[Sadie's Story|navigate the war-torn streets]] of New Mombasa with the help of Vergil in order to reach her father in the [[New Mombasa Data Center]]. However, the corrupt police commissioner, [[Kinsler]], in an act of vengeance against Sadie for refusing his previous sexual advances, has his men kill her father with [[argon]] gas by tripping the data center's fire suppression system. 
*During the fighting, the Covenant damage the Superintendent's data systems; a [[Quick to Adjust|lone Huragok]] survives and starts to repair the AI, saving Vergil by starting to absorb it into its own system. Kinsler, intending to take Sadie a prisoner as he leaves the city, is killed by Vergil after the subroutine allows a mob to tear him apart. Despite Sadie's pleas to stay and find him, Vergil sends her off on a [[NMTA|train]] with Mike towards [[Nairobi]], saving her life.
*'''1512 hours''': Designated a Tier One Asset, the UNSC identifies the Huragok as being at risk of being killed or captured by the Covenant.
*'''1557 hours''': Elsewhere in the city, ODST squad [[Alpha-Five]] participates in [[Operation: WINDOW PANE|an unsuccessful mission]] to retrieve a Forerunner device called the [[Conduit]] from Covenant hands.
*'''1602 hours''': As part of [[Operation: BUMRUSH|a mission]] to take down the ''Solemn Penance'' from orbit, [[Alpha-Nine|a squad of ODSTs]] led by ONI Captain [[Veronica Dare]] and [[Edward Buck|Gunnery Sergeant Edward Buck]], consisting of Corporal Taylor "Dutch" Miles, Lance Corporal Kojo "Romeo" Agu, [[Michael Crespo|PFC Michael "Mickey" Crespo]], and the Rookie, drop into New Mombasa from the {{UNSCShip|Say My Name}}. 
*'''1603 hours''': With Regret afraid of being overrun, the ''Solemn Penance'' initiates an in-atmosphere Slipspace jump to escape the city; while the ''In Amber Clad'' manages to pursue the carrier through the rift, the resulting explosion severely damages New Mombasa's infrastructure as well as scatters Alpha-Nine's [[SOEIV|drop pods]] across the city. 
*Having tailed Regret to Earth, a [[Jiralhanae]]-led Covenant [[Truth's fleet|occupation force]] is inserted into New Mombasa immediately after Regret's retreat as a part of the Prophet of Truth's plan to eventually [[Changing of the Guard|replace the Sangheili with the Jiralhanae]] as the Covenant's primary warrior race. For the rest of the day, UNSC and Covenant forces battle for control of the city. 
*'''1606 hours''': Gunnery Sergeant Buck lands at [[Tayari Plaza (location)|Tayari Plaza]] and assists Marine forces in combating the Covenant. Though he fails to link up with Captain Dare, he regroups with Lance Corporal Agu.
*'''1636 hours''': Corporal Miles assists an [[unidentified colonel]] in securing Regret's old landing zone within the [[Uplift Nature Reserve]]. 
*'''1649 hours''': Due to structural damage caused by the Slipspace explosion, the [[Mombasa Tether]] implodes and collapses, killing the colonel and scattering Marine forces into disarray. Miles manages to escape the reserve shortly after. By this point, the Covenant occupies 38% of the city.
*'''1736 hours''': PFC Crespo leads a [[Scorpion]] charge to assist Marines in clearing out [[Kizingo Boulevard (location)|Kizingo Boulevard]] and reaching their [[ONI Alpha Site (location)|rally point]], where he reunites with Miles.
*'''1806 hours''': Crespo and Miles aid the [[New Mombasa Police Department]] in preventing the Covenant from accessing important data housed in ONI's Alpha Site. 
*'''1852 hours''': The troopers are forced to fall back and extract via [[D77C-NMPD Pelican|police Pelican]] while Buck contacts Miles and Crespo to request a pick-up at the [[NMPD HQ|police headquarters]]. Crespo then detonates the Alpha Site to deny it to the Covenant.  The resulting explosion inadvertently awakens a large [[Yanme'e|Drone]] hive in the tunnels below the base. By this point, the Covenant occupies 51% of the city.
*'''1936 hours''': En route to the police HQ, Miles and Crespo's Pelican is shot down; Buck and Agu rescue them after a holding action that wounds Agu in the process.
*'''2106 hours''': Buck and his squad regroup; realizing the trains out of the city are flooded, they capture a [[Phantom]] at [[Kikowani Station (location)|Kikowani Station]] in an effort to escape.
*'''2141 hours''': Remaining Covenant cruisers coalesce over New Mombasa.
*'''2206 hours''': The Rookie wakes up from the drop and starts to search the streets of New Mombasa for his squadmates.
*'''2215 hours''': Cruisers begin excavation of the crater left behind by the Slipspace explosion, which Buck witnesses from Kikowani.
*'''2227 hours''': By this point, the Covenant occupies 78% of the city. 
*Having fled the area, Buck forces his squad to turn around after realizes where Dare went. 
*'''2319 hours''': Dare, having holed up in the city's data center, sights and reports the Tier One Asset Huragok in the tunnels.
*'''2324 hours''': By this point, the Covenant occupies 94% of the city.
*The Rookie receives Dare's distress call and fights his way through the data center to link up with her; together, they capture the Huragok, which by this point has fully absorbed the Superintendent (and Vergil) into itself.
*'''2359 hours''': Buck arrives to help secure the Huragok, now identified as Vergil.
*The Battle of Mombasa ends with a Covenant victory.

'''October 21'''
*Buck, Dare, and the Rookie defend the Huragok as they fight their way to the surface. 
*At dawn, the team witnesses continual Covenant reinforcements arriving at Earth to aid in excavation efforts. They flee down the city's [[New Mombasa Waterfront Highway|Waterfront Highway]] and reconnect with the rest of Alpha-Nine at the entrance to the Uplift Nature Reserve. The squad manages to hold out and eventually escapes New Mombasa as the city, along with its surroundings, are [[Glassing|glassed]] by the excavation fleet.

'''October 21 through November 17'''
*Following the Battle of Mombasa, Alpha-Nine and Quick to Adjust are kept in an [[ONI orbital facility]].<ref name="c9">'''Halo: New Blood''', Chapter 9</ref>

'''October 20 through November 2'''
*The Spartan-II Blue Team is deployed to defend Earth during the two weeks that follow the initial Covenant invasion. They participate in numerous combat missions on and around Earth, including [[Battle of Ross Island]] in the [[Wikipedia:Antarctica|Antarctica]] and an underwater operation in the [[Yucatan Peninsula]].
 
'''Late October'''
*The majority of the [[SPARTAN-III]]s of [[SPARTAN-III Gamma Company|Gamma Company]] are deployed into the battlefields of the Human-Covenant War, with only the top-ranked fireteams [[Team Saber|Saber]], [[Team Katana|Katana]], and [[Team Gladius|Gladius]] remaining on [[Onyx]] to compete for top honors.<ref>'''Halo: Ghosts of Onyx''', ''page 139''</ref>

'''October 25'''
*The Office of Naval Intelligence sends an exploration-and-neutralization team to [[Installation 03|Gamma Halo]].{{Ref/Reuse|11hour}}
*[[Skirmish on Mona Lisa|Skirmish on ''Mona Lisa'']]: The {{UNSCShip|Red Horse}} is sent to Installation 04's debris field in the Soell system to scout the area for survivors. They detect the [[prison ship]] ''[[Mona Lisa]]'' and deploy Marines into the ship. Soon after, it is revealed that the ship is infested by the Flood and was used by the Office of Naval Intelligence as a laboratory to test the parasite on prisoners. The infestation is contained as the ''Red Horse'' unleashes a [[Shiva-class nuclear missile]] on the ''Mona Lisa'', destroying it.<ref>'''Halo: Evolutions - Essential Tales of the Halo Universe''' - "The Mona Lisa"</ref><ref>[https://www.halowaypoint.com/en-us/forums/db05ce78845f4120b062c50816008e5d/topics/catalog-interaction/4c3e1c6f-6519-4ee0-83a4-4bac13bf07a3/posts?page=46#post454 '''Halo Waypoint''': ''Catalog Interaction'' (post 2976443)]</ref>

'''October 31'''
*The [[Onyx Conflict]] begins.
*The standby signal rouses the [[Onyx Sentinel|Sentinels]] of [[Onyx]], who destroy the UNSC base on the world.
*[[Team Gladius]] of the [[SPARTAN-III]] [[Gamma Company]] is totally wiped out by the Sentinels. [[Team Katana]] is forced into [[Zone 67]], and [[Team Saber]] loses contact with [[Camp Currahee]].
*Kurt-051, [[Franklin Mendez|SCPO Franklin Mendez]] and Petty Officers [[Tom-B292]] and [[Lucy-B091]] begin to form a resistance against the Sentinels.
*The {{UNSCShip|Agincourt}}, in high orbit above Onyx, is destroyed by Sentinels.
*Chief Mendez declares emergency code [[Bloody Arrow]] over the UNSC [[E-BAND]].

===November===
The end of 2552 saw the bloodiest period of the Great War and the beginning of the end. The Prophet of Truth was killed in the later months along with a sizable Covenant armada, leaving the Covenant forces crippled and leaderless as well as the full destruction of the [[Gravemind]] and its Flood forces.

'''November 2'''
*The [[Battle of Installation 05]] begins.
*The UNSC ''In Amber Clad'' arrives at [[Delta Halo]], following the High Prophet of Regret's assault carrier. John-117, aided by ODSTs and [[marine]]s, pursue the High Prophet to a Forerunner temple and assassinate him. However, orbital bombardment from the escorting fleets of the newly arrived [[High Charity]] destroys the temple. John-117 is thrown into a lake and captured by the Gravemind.
*The [[Changing of the Guard]] within the Covenant occurs.
'''November 3'''
[[File:H2A Great Schism.png|thumb|250px|Jiralhanae and Sangheili ships fighting over High Charity.]]
*The [[Great Schism]] begins.
*The [[Prophet of Conviction]] is killed by [[Unidentified Shipmaster (Righteous Vigilance)|one of his shipmasters]] after learning that Conviction ordered the killings of the Sangheili [[councilor]]s within the [[Fleet of Righteous Vigilance]].
*The Arbiter is sent to Delta Halo to retrieve that installation's [[Activation Index|Index]]. The Arbiter is successful, but is then betrayed by [[Tartarus]], who casts the Arbiter into the depths of the ringworld. The Arbiter is subsequently captured by Gravemind.
*Gravemind sends John-117 and the Arbiter to secure the Index and prevent the installation from being activated. John-117 is teleported to High Charity while the Arbiter is teleported close to the Control Room. Both are aided by the chaos of the Covenant civil war.
*The Flood controlled ''In Amber Clad'' jumps inside High Charity and commences its infection. The [[Prophet of Mercy]] becomes infected by the Flood.
*John-117 is unable to prevent the Index from leaving High Charity with Tartarus. Instead, on the advice of Cortana, the Spartan stows away aboard the [[Forerunner Dreadnought]] that is carrying the [[High Prophet of Truth]] to Earth. Cortana remains behind to ensure the destruction of Installation 05, should that become necessary.
*Cortana sends a slipspace message to Earth informing them that John-117 is en route.
*The Arbiter reaches Installation 05's Control Room but is unable to prevent Tartarus from activating the ring. With the help of humans and the [[Sangheili]], the Arbiter kills Tartarus. This allows Commander Keyes to physically remove the Index from [[the Core]], temporarily interrupting the firing sequence. Due to the interruption, Installation 05 automatically sends a signal to all other Forerunner installations in the galaxy, activating and placing them in standby mode.
*The {{UNSCShip|Dusk}} arrives at Delta Halo and witnesses the final stages of the Battle of Installation 05. She retreats to Earth via an anomalous [[Slipstream space#Slipspace wake|slipspace wake]] caused by the Forerunner ship.
*Dr. Halsey and [[Kelly-087]] arrive at Onyx and are trapped along with the rest of the human survivors. Halsey sends a distress signal piggybacked on Cortana's October 28 signal.
*The [[Battle of Havana]] is fought. [[William-043]], Linda-058, and [[Frederic-104]] manage to stall the Covenant's forces in [[Havana]], [[Wikipedia:Cuba|Cuba]] by destroying the [[Centennial Orbital Elevator]]. They receive new orders from Dr. Halsey to redeploy from Earth to Onyx, capture the Covenant destroyer ''[[Bloodied Spirit]]'', and depart for Onyx.
*[[Voro 'Mantakree]] is promoted to [[Fleet Master]] by [[Imperial Admiral]] [[Xytan 'Jar Wattinree]], and is given the mission to intercept the Spartans heading for Onyx and to retrieve the Forerunner technologies said to be there.
*Danforth Whitcomb's [[NOVA bomb]] detonates on board the Covenant supercarrier ''[[Sublime Transcendence]]'', in orbit above the Sangheili outpost world [[Joyous Exultation]], destroying every ship in the vicinity, and also scorching a quarter of Joyous Exultation and completely vaporizing the nearby moon [[Malhiem]].
*The ''Dusk'' arrives at Earth after mere hours. Upon arrival, she is reassigned to [[Battle Group Omicron]]. The group jump to Onyx via the ''Bloodied Spirit''<nowiki>'</nowiki> slipspace wake.
*[[Blue Team]] arrives at Onyx aboard the captured ''Bloodied Spirit'', and links up with Kurt-051, Kelly-087, Dr. Halsey, Chief Mendez, and the SPARTAN-III's. They proceed to push forward into Zone 67, retreating further underground when a newly arrived [[Joyous Exultation Covenant|Covenant]] fleet begins landing troops.
*[[Admiral]] [[Carl Patterson|Patterson]]'s [[Patterson's battle group|battle group]] arrives at Onyx to retrieve the survivors, but is unsuccessful due to the Covenant presence. The UNSC battlegroup is destroyed, with the exception of the ''Dusk'', which avoids destruction by remaining stealthed.
*After an emergency mission redirect by the ONI AI [[Endless Summer]], Kurt-051 and his forces proceed to destroy the [[Sentinel manufacturing facility|Sentinel factory]] in Onyx's polar region and retrieve Team Katana, enclosed within [[slipspace field pod]]s.
*Onyx is found to be an artificial structure built by the Forerunners to house a [[shield world]]. The human survivors hold off pursuing Covenant troops long enough to flee to the safety of the shield world.
*Kurt promotes [[Frederic-104]] to [[Lieutenant, Junior Grade]].
*[[Kurt-051]] dies after detonating 2 FENRIS warheads inside Onyx's [[core room antechamber]].
*The Onyx Conflict ends. Sentinels annihilate the remaining Covenant forces as Onyx's artificial landmass disintegrates.
*[[Chol Von]], a [[T'vaoan]] [[Shipmaster|shipmistress]], renamed her [[missionary ship]] ''[[Paragon|Joyous Discovery]]'' as ''Paragon'' at some point of the Great Schism.<ref name="md141">'''Halo: Mortal Dictata''', ''page 141''</ref> During the Schism, she captured a [[Phantom]], killing two [[Sangheili]] in the process.<ref>'''Halo: Mortal Dictata''', ''page 73''</ref>

'''November 4'''
*In an effort to contain the Flood outbreak, [[Fleet of Retribution|Thel 'Vadam's Covenant faction]] begins glassing Installation 05's surface and proceed to destroy any ships leaving the ring.{{Ref/Marketing|Id=LongRoad|Halo Waypoint|The Long Road Home}}<ref>'''[[Eleventh Hour reports]]''', ''Heirlooms''</ref>
*Cortana is deposited into ''High Charity''{{'}}s distributed network.<ref name="DD">'''[[Halo Legendary Crate]]''', ''[[Halo Legendary Crate/Data Drops|Data Drop #9]]''</ref>

'''November 7'''
*A [[Catalog]] unit, having been dormant for 100,000 years after the firing of the Halo Array, resumes its duties after receiving and denying a control authorization supposedly sent by the [[Librarian]].<ref>[https://forums.halowaypoint.com/yaf_postsm2963929_Catalog-Interaction.aspx#post2963929 '''Halo Waypoint''': ''Catalog Interaction'']</ref>

'''November 8'''
*The Prophet of Truth arrives in the [[Sol system]] aboard the Forerunner Dreadnought, and proceeds on course towards Earth at near-relativistic speeds.<ref name="timeline">[http://halo.bungie.net/News/content.aspx?type=topnews&cid=16989 '''Bungie.net''': ''Bungie Weekly Update: 01/23/09'']</ref> However, due to John-117's presence aboard the vessel the ship's crew becomes preoccupied with finding and eliminating the Spartan.{{Ref/Reuse|LongRoad}}

'''November 8 through November 15'''{{Ref/Reuse|lootcrate2}}
*[[Sergeant Major Johnson]] and [[Miranda Keyes|Commander Keyes]] arrive back at Earth from Installation 05.

'''November 8 through November 17'''
*The [[Battle of Mare Erythraeum]] takes place on [[Mars]]. Following the battle, Colonel James Ackerson, commander of the UNSC forces on Mare Erythraeum, is taken hostage and interrogated by the Jiralhanae Commander [[Lepidus]] on board the Covenant cruiser ''[[Triumphant Declaration]]'', who tells them of a Forerunner device linked to the [[Halo Array]] known as the [[Key of Osanalan]], and that it can be found in [[Cleveland]], [[Ohio]]. In reality, the Key of Osanalan is made up as a ploy by James Ackerson to prevent Cleveland from being glassed as part of the battle on Earth in a bid to save the life of his brother, [[Ruwan Ackerson|Ruwan]], who lives there.
*[[Battle of Cleveland]]: Covenant forces, looking for the Key of Osanalan, invade the city of Cleveland. After Ruwan learns the reason the Covenant are invading, he devises a plan with [[Twyker|Sergeant Twyker]]. 

'''November 10'''
*The [[URNA Southwest Campaign]] begins as Covenant forces start to excavate and occupy built-up positions centered around [[Free-fire Area OZONE]] in [[Arizona]], [[URNA]].{{Ref/Reuse|lootcrate2}}

'''November 15'''
*'''1649 hours''': Sergeant Major Johnson gets clearance from [[Lord Hood]] to question [[Vergil]] about [[Portal at Voi|the artifact]] the High Prophet of Truth is digging up near Voi.{{Ref/Reuse|lootcrate2}} Captain Dare participates in the interrogation.
*'''1725 hours''': AI [[Barca]] generates the interrogation into a [[ONI Directorate Memorandum Interrogation Findings|report]] for Lord Hood.{{Ref/Reuse|lootcrate2}}

'''November 17'''{{Ref/Reuse|timeline}}
[[File:S117returnstoEarth2552.jpg|thumb|250px|John-117 and the Forerunner Dreadnought entering Earth's atmosphere.]]
*Believing the Spartan to be dead, the Prophet of Truth orders the crew of the Forerunner Dreadnought to jump further in-system and enter Earth's atmosphere.{{Ref/Reuse|LongRoad}} 
*The Dreadnought arrives at Earth, and John-117 makes contact with Lord Hood aboard the ''Cairo''.<ref>'''Halo 2''', level ''[[The Great Journey (level)|The Great Journey]]''</ref> Shortly after, the Spartan is ordered to find a way off the ship to avoid being caught in the impending destruction of a nearby Covenant cruiser, ''[[Harbinger of Piety]]''.<ref name="Issue 4">'''Halo Uprising''', ''[[Halo: Uprising Issue 4|Issue 4]]''</ref>
*Injected with an [[Tykos 30|organic tracking material]], Ruwan, claiming to the Covenant that he himself is the Key, is taken aboard the cruiser ''[[Harbinger of Piety]]'', where the [[Minister of Inquisition]] vows to spare Earth in exchange for Ruwan's knowledge. [[Nassau Station]] then uses its [[Magnetic Accelerator Cannon]] to obliterate the ''Piety'' and everyone on board.{{Ref/Reuse|Issue 4}}{{Ref/Note|''Halo: Uprising'' establishes that the ''Piety'' and Dreadnought are in the same vicinity at this time, indicating Ruwan's actions take place on this date.}}
*John-117 proceeds to eject from the ship, using a hatch as a heat shield upon re-entry. Meanwhile, [[Battle of Sector Six]] takes place at [[Sector Six]]. There, numerous Marines of the [[2nd Orbital Drop Shock Trooper Battalion|2nd ODST Battalion]] track John-117's descent. John-117 eventually lands in the [[Tanzania]]n jungle near [[Mount Kilimanjaro]], going unconscious for hours.
*The Prophet of Truth's Dreadnought lands in the middle of [[the Portal]] near [[Voi]], [[Kenya]]. During the last few weeks, Truth's fleet have almost entirely uncovered the Portal and occupied the entire region surrounding it.
*After the Key of Osanalan is revealed to be a ruse, Lepidus executes Ackerson aboard ''Triumphant Declaration''.
*UNSC forces [[Recovery of John-117|recover]] John-117 from a jungle near [[Mount Kilimanjaro]]. In the underground facility of [[Crow's Nest (location)|Crow's Nest]], a plan is formulated to launch an aerial strike on Covenant anti-air defenses in the town of [[Voi]] in order to prevent the Prophet of Truth from activating the Forerunner artifact. After repelling a [[Attack on Crow's Nest|Covenant assault]] on Crow's Nest and destroying the base in the process, a UNSC strike force led by John-117 [[Assault on the Tsavo Highway|retakes]] the Covenant-held [[Tsavo highway (location)|Tsavo Highway]].
*[[Battle of Voi]]: John-117 and a Marine strike force enter Voi and gradually push back the city's Covenant occupiers, destroying the Covenant anti-air defenses in the city. An [[Battle Group Victory|aerial strike force]] consisting of the {{UNSCShip|Forward Unto Dawn}} and at least six other frigates<ref name="mythos">'''[[Halo Mythos]]''', ''page 117''</ref> as well as numerous Longsword fighters assaults the Forerunner Dreadnought resting over the Portal artifact, but are unsuccessful in damaging the ship. Truth activates the portal and retreats through it to [[Installation 00]] along with his forces. At the same moment, a [[Indulgence of Conviction|Flood-controlled ship]] slips in, crashing in Voi.
*Covenant battlenet cohesion breaks down after Truth's departure, allowing UNSC forces in the southwest URNA to begin a major counteroffensive as part of their ongoing campaign.{{Ref/Reuse|lootcrate2}}

[[File:H3 TheArk Opening.jpg|250px|thumb|The Ark portal on Earth activates.]]

*UNSC forces make their way toward the crashed ship in order to overload its reactors and contain the Flood outbreak, just as the Sangheili [[Fleet of Retribution]] arrives and drops in reinforcements. After recovering a message by [[Cortana]] from the Flood ship, John-117 and the remaining human and Sangheili forces retreat from Voi, as the Fleet of Retribution glasses the city and its surroundings in order to contain the Flood.
*UNSC and Sangheili leaders gather aboard the Sangheili assault carrier ''[[Shadow of Intent]]'' to hear Cortana's message, which reveals there is a way to stop the Flood on the other side of the Portal. Despite Lord Hood's argument to stay and defend Earth from an encroaching now-Flood-infested High Charity, Commander Keyes, along with the Master Chief and the Sangheili, enter the Portal with the Fleet of Retribution and the ''Dawn'', leaving Hood behind to coordinate Earth's remaining defenses.

'''November 18'''
*'''1545 hours''': High Charity arrives at Mars and makes a slipspace jump to the lesser Ark.<ref>[https://forums.halowaypoint.com/yaf_postsm2959975_Query--Catalog.aspx#post2959975 '''Halo Waypoint''' - ''Query: Catalog'']</ref>
*The {{UNSCShip|Crassus}} is spotted by [[Jiralhanae]] hunting parties and boarded. However, after capturing the flight deck, the Jiralhanae and [[Unggoy]] attackers have difficulty pushing into the vessel's cramped interior. The resulting stalemate convinces the Jiralhanae to withdraw, settling on destroying the [[supercarrier]]'s flight tower as they depart.{{Ref/Site|Id=CFStrike|URL=https://www.halowaypoint.com/news/canon-fodder-ship-strike|Site=Halo Waypoint|Page=Canon Fodder - Ship Strike|D=22|M=04|Y=2023}}

'''November 19'''
*'''0630 hours''': At Free-fire Area OZONE in Arizona, UNSC flagword [[LUX]] is declared and a [[UEG]] emergency evacuation broadcast is initiated. 
*'''0700 hours''': The UNSC uses nuclear weapons against multiple shielded Covenant positions.{{Ref/Reuse|lootcrate2}}

===December===
[[File:H3 LesserArkConflict.png|250px|thumb|A battle rages above Installation 00.]]
'''December 3'''
*Admiral [[Joseph Harper]] initiates [[Operation: MARSH FLASH]] in Arizona, eliminating clusters of high-ranking Jiralhanae leadership attempting to activate an artifact at Free-fire Area OZONE, effectively bringing a close to the [[URNA Southwest Campaign]].{{Ref/Reuse|lootcrate2}}
'''December 11'''<ref>[http://halo.xbox.com/en-us/intel/featured/video/herofortitude/bfe5038b-314a-4f17-a6be-f7613e0e3788 '''Halo Waypoint''', ''Hero-Fortitude'']</ref><ref name="vociwaypoint">[https://www.halowaypoint.com/en-us/forums/db05ce78845f4120b062c50816008e5d/topics/glasslands-complaints/4e36f9a8-65f0-4d0b-bfbc-3c9d3e4b263c/posts?page=5#post100 '''Waypoint''': ''Glasslands complaints...'' forum thread]</ref>
*The [[Battle of Installation 00]]: The joint Sangheili-human force arrives at Installation 00 and immediately engages Truth's forces while the {{UNSCShip|Forward Unto Dawn}} deploys ground forces to locate Truth. Despite being outnumbered three to one in space, the separatist fleet makes short work of the Covenant space forces. After locating Truth via the Cartographer, the separatist-UNSC alliance launches an assault on the Ark's [[Forerunner Citadel|Citadel]] where Truth intends to activate the Halo Array. At the same time the former Covenant city ship High Charity arrives from slipspace and crashes on the Ark. Debris spread from the city-ship helps spread a new Flood infestation on the Ark. The Sangheili and UNSC finish off the last stand of the Covenant's resistance, consisting of two Scarabs and many other ground forces, in [[Battle of the Citadel|a large battle]] before the Citadel.  
[[File:TruthDeath-large.jpg|250px|thumb|The death of Truth and the Covenant's end.]]
*Miranda Keyes is killed when she attempts to rescue Johnson from Truth inside of the Citadel. With Truth moments away from activating the Halo array, John-117 and the Arbiter temporarily ally themselves with the Flood and storm the Citadel. They shut down the Halo array, and the Arbiter executes Truth, finally ending the Human-Covenant War. 
*'''The Human-Covenant War ends.'''
*The Flood immediately turn against John-117 and 'Vadam, but the pair escape.  Soon after, it is discovered that the Ark's foundry has created [[Installation 08|a replacement]] for the destroyed Installation 04. Realizing that the ring could be used to fire a tactical pulse which would eliminate the Flood infestation, John-117 decides to light it. In order to do so, he enters the ruins of High Charity and recovers Cortana, who still possesses the Activation Index from the original Installation 04. High Charity is destroyed in the process.
*With the Index secure, John-117, Cortana, the Arbiter, and Sergeant Major Johnson travel to the replacement Installation 04, while the rest of the UNSC and Sangheili forces return to Earth on the ''Shadow of Intent''. In the control room, Johnson is killed as 343 Guilty Spark attempts to prevent him from activating the ring prematurely, as doing so would destroy the ring. John-117 destroys the monitor and begins the firing sequence for the Halo ring. John-117 and the Arbiter then escape the control room by taking Johnson's Warthog to the UNSC Frigate ''Forward Unto Dawn'', which is holding position nearby.
*Due to the unstable, incomplete nature of the ring as it fires, the slipspace portal collapses as the ''Dawn'' enters it, causing it to be sheared in two. The Halo ring explodes causing heavy damage to the Ark, rending both defunct. Cortana and John-117 are in the hangar area at the time of the Frigate's separation, and are thus left in the aft section of the ship, which falls out of Slipstream space at an unknown location, eventually drifting towards a Forerunner [[shield world]], [[Requiem]].

'''December 14'''
*[[000 Tragic Solitude]] orders his sentinels to begin the construction of a [[containment shield]] around the remains of High Charity for quarantine.<ref name="AUT">'''Halo Wars 2''', ''[[Phoenix Logs]] — Idle Hands Part 2''</ref>

'''December 15'''
*John-117 has an augmentation maintenance scheduled for this date.<ref name="Background">[https://www.youtube.com/watch?v=gzBDfIX_Wik ''Youtube'', Halo: The Master Chief Collection - Wake Up, John]</ref>

'''December 23'''
*[[Arbiter]] [[Thel 'Vadam]] returns to Earth using the forward half of the ''Dawn'', crashing into the Indian Ocean.{{Ref/Reuse|vociwaypoint}}

'''December 30'''
*The ''Shadow of Intent'' is repaired and refitted at a mobile shipyard.<ref name="Catalog">[https://forums.halowaypoint.com/yaf_postsm2969315_Catalog-Interaction.aspx#post2969315 '''Halo Waypoint''': ''Catalog Interaction - Page 14'']</ref>

'''December 31'''
*[[Codename: SURGEON]] filed a report to [[Codename: USUAL SUSPECTS]] entitled "[[Historical/Psychological Analysis of Cole, Preston J.]]" The report was filed from {{UNSCShip|Point of No Return}} in synchronous orbit on the far side of [[Luna]].<ref>'''[[Halo: Evolutions]]''' - ''[[The Impossible Life and the Possible Death of Preston J. Cole]]'', pages 413-487</ref>

'''Unknown date'''
*Unaware of the Human-Covenant War's conclusion not long earlier, the Spartan-II Gray Team destroy the [[Sangheili colony]] of [[Glyke]] with a [[NOVA bomb]] according to [[Operation: SUNSPEAR]]'s Condition Endgame.<ref>'''[[Halo: Envoy]]''', Chapter 4</ref>

==Battles==
'''[[Human-Covenant War]]'''
*[[Battle of Beta Eridani]]
*[[Operation: FIRESIDE]]
*[[Battle of Fumirole]]
*[[Massacre of Troy]]
*[[Battle of Sigma Octanus IV]]
*[[Fall of Reach]] ([[Template:Engagements in the Fall of Reach|Engagements]])
*[[Battle of Tribute]]
*[[Raid on Verge]]
*[[Battle of Beta Gabriel]]
*[[Battle of Line Installation 1-4]]
*[[Battle of New Jerusalem]]
*[[Raid on Mount Haven]]
*[[Battle of Installation 04]] ([[Template:Engagements in the Battle of Installation 04|Engagements]])
*[[Massacre at Eridanus Secundus]]
*[[Operation: FIRST STRIKE]]
*[[Battle of Earth]] ([[Template:Engagements in the Battle for Earth|Engagements]])
*[[Battle of Installation 05]] ([[Template:Engagements in the Battle of Installation 05|Engagements]])
*[[Onyx Conflict]]
*[[Battle of Mare Erythraeum]]
*[[Scramble onboard Forerunner Dreadnought]]
*[[Battle of Installation 00]] ([[Template:Engagements in the Battle of Installation 00|Engagements]])
*[[Operation: SUNSPEAR]]

'''The Great Schism'''
*[[Fall of High Charity]]

'''Other/Unknown'''
*[[Battle of October 10]]
*[[Battle of the Gas Mine]]

==Trivia==
*All five ''Halo'' games developed by [[Bungie]] take place in the latter half of this year.
*The numerical value of the year is one of Bungie's many references to the number [[seven]]. Specifically, adding the numerals results in 14, which has twice the value of 7. Adding the two halves of the year separately (2+5 and 5+2) results in a pair of sevens.

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

==Sources==
{{Ref/Sources|2}}