Battle for Earth

"We ran from them. They followed. We thought they'd never find us... we were wrong."

- Cortana

The Battle for Earth, also referred to as the Earth Sustained Defense Campaign, was one of the largest, bloodiest and latest engagements fought between the Covenant and the forces of the Unified Earth Government (primarily those of the United Nations Space Command), at the end of the approximately twenty-seven year-long Human-Covenant War, which took place on and above the planet Earth from October 20 to not before December 3, 2552. It was one of the most important battles of the war, as the fate of humanity depended on the survival of its homeworld and seat of its government.

Though the invasion took place on a global scale, the most significant conflicts occurred in the East African Protectorate in the form of three battles fought within and between the cities of Mombasa and Voi, collectively referred to as the first, second, and third battles of Mombasa. The conflict began when the Fleet of Sacred Consecration, under the command of the Prophet of Regret, arrived on October 20 with intentions of traveling through the portal that a luminary in its possession pointed to. This move was made without the consent of the other two Hierarchs and in ignorance regarding the status of this planet as humanity's homeworld. Faced with the full might of the UNSC Home Fleet, it was not long before Regret's flagship fled to Installation 05. Soon after this, the Prophet of Truth initiated his plans to replace Sangheili with Jiralhanae and assume control over the entirety of the hierarchal triumvirate. A second fleet, led by Jiralhanae, appeared in the system and quickly assumed control of all local Covenant forces by killing all Sangheili.

At this point, the fight for Earth began in earnest. Smaller battles were waged all across the world, from the UEG capital of Sydney, Australia, to Cleveland, URNA, to Havana, Cuba, and to Mount Erebus, Antarctica and multiple other locations. By November 17, most of the Home Fleet had been obliterated. It was on this date that the Prophet of Truth himself, aboard the Forerunner Dreadnought and with Spartan-117 in tow, arrived and headed straight for the Excession, by then fully excavated. Upon interfacing with the keyship, the portal was activated and a large contingent of the Covenant fleet departed through the Portal with the intention of activating the Halo Array from the Ark. Almost immediately after this, the Flood arrived aboard a captured, which crashed down in the town of Voi. The Fleet of Retribution, allied with the UNSC against Truth, was permitted to glass a large portion of Africa to prevent the parasite's spread. With the threat from the Flood dealt with and the bulk of Covenant forces gone, at least one UNSC frigate accompanied the Fleet of Retribution in pursuit of Truth. The remainder of UNSC forces remained behind to defend Earth from an expected full-scale Flood invasion and also began a major counteroffensive to eliminate all Covenant that remained.

Background
The Human-Covenant War was a decades-long conflict wherein the Covenant hegemony was determined to exterminate all of humanity at the behest of its three Hierarchs, who mistakenly believed humans' to represent the living embodiment, and thus discreditation, of their religion's gods. Also a goal of the empire, from long before first contact with humanity, was the location and activation of the Halo rings. In the aftermath of the Fall of Reach, the UNSC began to pull the majority of its forces back to Earth, with most units assigned to defend Earth's six tether cities. The Prophet of Regret learned "Erde-Tyrene" held a portal which led to the Ark and the Prophet of Truth simultaneously discovered the planet's location through other means.

Formation of the Home Fleet
From May 14–19, 2552, UNSC forces in the Earth Defense Coordination Zone were placed at maximum readiness levels and all warships with magnetic accelerator cannons self-deployed or towed to rally points. Cairo Station was established as flag headquarters. On September 5, 2552, all remaining naval forces were consolidated into a single command grouping: the UNSC Home Fleet. Fleet Admiral Joseph Harper was appointed senior flag officer 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. Remaining expeditionary and defense fleets retained administrative control over their battle groups, though all type commands were dissolved.

Earth compromised


The Prophet of Truth discovered the location of Earth after the Fall of Reach, but withheld knowledge of this discovery from the rest of the Covenant leadership. To attack the human homeworld, he ordered an assault fleet to secretly assemble at Unyielding Hierophant station in the Tau Ceti system. The fleet would overwhelm Earth's defenses in a single decisive strike. The fleet was discovered by the UNSC AI Cortana and preemptive strike was led by Vice Admiral Danforth Whitcomb and a SPARTAN-II, strike team, which successfully destroyed Unyielding Hierophant and almost the entirety of the assembled fleet, some five hundred ships. Earth was granted a small reprieve.

The Prophet of Regret also independently learned of the location of Earth as the location of a Forerunner artifact, the Portal leading to the Ark. This revelation came after long study by stewards of a Forerunner luminary taken from the moon, Meridian, in 2551. Not being privy to Truth's information, Regret set off to uncover the artifact without any knowledge that Earth was the humans' homeworld. Regret unknowingly led his small fleet, a mere two assault carriers and thirteen battlecruisers, straight into Earth's formidable defenses. Truth belatedly learned of Regret's expedition to Earth, and dispatched a large Jiralhanae-led fleet to reinforce the attack. They arrived mere hours after Regret had fled.

Regret's arrival
"Something's not right. The fleet that destroyed Reach was fifty times this size!"

- Fleet Admiral Terrence Hood

The High Prophet of Regret's fleet was detected near Jupiter's moon Io, as a series of slipspace "whispers". Probes were sent to investigate, but shortly afterwards the Covenant fleet exited slipspace near Earth, just outside the killzone of the planet's orbital defense platforms. UNSC forces went to TACCON Alpha 2. Fleet Admiral Harper ordered his battle group to attack, but quickly received new orders from Fleet Admiral Terrence Hood to fall back and defend the ODPs. Having expected an overwhelming enemy offensive in the style of the Battle of Reach, the relative weakness of the attack puzzled the defenders.

The assault carriers converged on the battle cluster including Athens Station, Cairo Station and Malta Station. The ODPs opened fire as the enemy entered range. Covenant troops boarded the stations, intending to demolish them with an antimatter charge each. As each bomb was planted the Covenant withdrew. Athens and Malta were demolished in quick succession. Cortana, aboard Cairo, deduced the nature of the threat and John-117 was dispatched to prevent the same fate from befalling Cairo.

Cortana directed the SPARTAN-II to the bomb's location in Cairo's fire control center. En route to the bomb, John-117 rescued Commander Miranda Keyes and allowed her to board. The frigate departed Cairo to join the fray.

Meanwhile, Harper's Fifth Fleet continued to engage the Covenant task force in Earth orbit, sustaining huge losses in the wake of the Covenant's superior firepower but still prevailing through sheer numbers against the unusually small Covenant force. However, even as their escorts were effectively routed by the UNSC, the two assault carriers pushed onward, bypassing much of the already battered human fleet even as they too came under fire.

Covenant breakthrough
"The carriers are breaking through sir, they're headed straight for the Cairo!"

- Fleet Admiral Harper

The two assault carriers began to break through toward Cairo. Cortana directed Cairo's MAC against the Solemn Penance, but the ship did not stop to engage and instead made directly for New Mombasa on the surface. Admiral Harper led the attack on the second carrier and depleted its shields. Keyes volunteered to attack the carrier immediately, but Hood was unwilling to pit a single frigate against so large a target.

The solution to the second carrier came from an unexpected angle. John-117 and Cortana managed to defuse and capture the Covenant antimatter bomb aboard Cairo, and the Spartan volunteered to go EVA and personally plant the bomb on the last carrier. With Lord Hood's approval, John-117 leapt out of an airlock with the bomb using only the initial explosive decompression for impulse. Longsword interceptors opened a breach in the carrier's hull and allowed the Spartan to infiltrate and plant the bomb internally. The detonation destroyed the ship. John-117 escaped using the same means he had arrived and free fell to the UNSC In Amber Clad.

Regret flees
"Dear humanity, we regret being alien bastards, we regret coming to Earth, and we most definitely regret the Corps just blew up our raggedy-ass fleet!"

- Avery Johnson commenting on Regret's message

Regret's carrier came to stop over New Mombasa in the East African Protectorate and deployed troops into the city and the surrounding area. UNSC high command wished to discover why the Covenant were landing only in Mombasa, and John-117 was ordered to capture Regret for interrogation. The Spartan deployed with marines and ODST in a trio of Pelicans from the near the city. The dropships were shot down by a Covenant Scarab in Old Mombasa. John-117 and the survivors regrouped and pursued the walker to NM 105E, and across the bridge to New Mombasa Sector B. The Scarab was eventually trapped and destroyed at the end of a canal. Covenant forces started to withdraw to the carrier for slipspace departure.

In orbit the Home Fleet began deploying ODSTs to Mombasa in SOEIVs, intending to board the the carrier and capture the Prophet of Regret. One Squad, Alpha-Nine, deploying from the and led by Gunnery Sergeant Edward Buck, was diverted by ONI to secure the city's infrastructure AI.

Regret's means of escape took the UNSC by surprise. The carrier initiated a slipspace jump while still over the city. The UNSC In Amber Clad quickly recovered John-117 and followed in the fleeing ship's wake. The slipspace rupture severely damaged the city and generated an EMP. Many ODSTs had not yet landed when the carrier escaped and were caught in the EMP and blast. Drop pods were disabled in flight and plunged into uncontrolled freefall. Those who survived the blast were scattered across the city.

Truth's fleet arrives
"The Covenant have found Earth. They own New Mombasa. Anyone that could've driven them off is dead, or gone. I'd say that makes for desperate times."

- Edward Buck

Immediately following the slipspace event, Jiralhanae forces loyal to the High Prophet of Truth, who had embedded said troops into his political Rival Regret's fleet, enacted their leader's orders. The Jiralhanae violently displaced their Sangheili commanders both ground-side, and in orbit, the beginning of Truth's plan to place the Jiralhanae as the Covenant's primary warrior race. Additional Jiralhanae led-Covenant ships sent by Truth also began to arrive in the Sol System, joining the remains of Regret's fleet in the assault upon Earth.

Surviving UNSC forces in the city, aided by the New Mombasa Police Department, continued to resist, but were eventually overwhelmed. The Covenant began glassing Mombasa and the surrounding area, uncovering the Portal to the Ark. Captain Dare and her ODST squad managed to secure the city's infrastructure AI and escape before the city fell to the enemy.

Covenant occupation
The battle spread over the globe in the following weeks. The diminishing UNSC Home Fleet, in conjunction with the Second, Seventh, and Sixteenth Fleets, remained to contest Earth orbit, but the Covenant continued to raid the surface in search of Forerunner artifacts, mostly concentrating in east Africa.

The Spartan Blue Team, consisting of Frederic-104, Linda-058, and William-043, were constantly engaged for the first two weeks. They repelled enemy ships in orbit in numerous zero-gee operations whilst on the surface they neutralized Covenant excavations, first on Ross Island in Antarctica, and then underwater off the Yucatan Peninsula. On November 3, they were deployed to Havana, Cuba, where they stole the enemy destroyer Bloodied Spirit, and destroyed another destroyer and the Centennial Orbital Elevator. They subsequently redeployed aboard the stolen ship to the Forerunner shield world Onyx to aid Dr. Catherine Halsey, the creator of the SPARTAN-II program.

On November 10, Covenant forces began to excavate and occupy built-up positions centered around Free-fire Area OZONE in Arizona, URNA.

The UNSC's loss of their garrison on Mars following the Battle of Mare Erythraeum led to a dramatic increase in Covenant force deployments on Earth. Shortly after the loss of Mars, Covenant also invaded the city of Cleveland on Earth, looking for an artifact known as the "Key of Osanalan". The Key turned out to be a hoax perpetrated by Colonel James Ackerson; this attack was ultimately repelled due to the Colonel's act of self-sacrifice, and that of his civilian brother, Ruwan.

Sydney, Australia was one of the cities invaded by the Covenant during the engagement. Though the city suffered heavy damage by Covenant bombardment, the UNSC's HIGHCOM Facility Bravo-6 remained undamaged.

Near the conclusion of the Battle of Installation 05, the Prophet of Truth departed High Charity, near Halo Installation 05, in the Forerunner Dreadnought on November 3, arriving at the Sol system on the 8th. The prophet sought to activate the Ark, fire the Halo Array, and begin what he thought would be the "Great Journey". Unbeknownst to the Covenant, John-117 had stowed away aboard the ship.

Whilst on Installation 05, Commander Miranda Keyes, Sergeant Major Avery Johnson, and Arbiter Thel 'Vadam learned of the Prophet of Truth's intentions and departed the installation after the Dreadnought while Rtas 'Vadum and the Sangheili under his command stayed behind on Installation 05 in order to quarantine and glass the Halo ring as well as quarantine High Charity in order to stop the escape of the Flood and the Gravemind from both the Halo and the city. Upon arrival at Earth on or just before November 15, they took up station in an old military base, Crow's Nest, near Voi, and waited for John-117 to arrive.

Truth's arrival
"Fleet Admiral Terrence Hood"



The Forerunner Dreadnought arrived at Earth on November 17, spearheading the final contingent of Truth's forces. The Covenant fleet breached the Lunar perimeter, devastating the remnants of the UNSC Home Fleet. The subsequent bombardment caused "extreme" casualties. As the Dreadnought entered Earth's atmosphere, John-117 left the ship by leaping off during re-entry and crashing into the East-African jungle. By this time the Covenant had set up heavy AA batteries and other defenses near Voi and in the surrounding area to protect their work at the Portal.

During Spartan-117's re-entry, a pair of ODSTs used a laser designator during the Battle of Sector Six in Afghanistan to track the Spartan's fall. The data made it easier for Sergeant Johnson and Thel 'Vadam to locate the Spartan. After making their way through the jungle, they were extracted by a dropship, despite Covenant resistance, and taken to Crow's Nest. The Covenant tracked them back to the base, however, and launched an attack.

UNSC counterattack
"Marines, the Prophet of Truth doesn't know it yet, but he's about to get kicked right off his throne. You will take our city back. And drive our enemy into the grave they've been so happily digging. One final effort is all that remains."

- Admiral Terrence Hood

Commander Keyes proposed to destroy the Covenant anti-air defenses at Voi, allowing low flying frigates to strike the Forerunner Dreadnought now landed on the Portal. Fleet Admiral Terrence Hood had only a few frigates left, but was willing to commit to the risky plan with John-117's recovery.

Just before the UNSC offensive began, the Covenant attacked Crow's Nest. Miranda Keyes evacuated and destroyed the base with a bomb before it could be occupied. John-117 barely managed to escape the destruction of the facility but met up with Gunnery Sergeant Reynolds and set out in Warthogs on Tsavo Highway to head for Voi, as did scattered UNSC forces, engaging Covenant heavy vehicles along the way.

At Voi, the UNSC broke through Covenant defenses, as John-117 and Thel 'Vadam disabled a Covenant AA battery. With the path to the Portal cleared, Fleet Admiral Hood ordered three frigates and multiple Longswords to attack the Forerunner Dreadnought. Despite MAC fire, the enemy ship remained intact and was able to activate the Portal. The Dreadnought and the remaining Covenant ships departed Earth through the resulting Slipspace portal. Covenant battlenet cohesion broke following Truth's departure, allowing UNSC forces in the southwest URNA to begin a major counteroffensive as part of their ongoing campaign.

The Flood on Earth
"Quickly! Let us find their ship. Make short work of this abomination!"

- Thel 'Vadam

While the battle for Earth raged, the Covenant had been attempting to maintain a quarantine of the Flood-infested High Charity and Installation 05. The Flood-controlled Indulgence of Conviction escaped and arrived at Earth as the Prophet of Truth departed through the Portal. The ship crashed in Voi and began infesting the area. John-117 and Thel 'Vadam quickly made for the crash site intending to overload the ship's reactor. The explosion would destroy the city but would hopefully stop the spreading infestation as well.

Sangheili ships, led by Fleet Master Rtas 'Vadum aboard the assault carrier Shadow of Intent, arrived in pursuit of the Flood. The Sangheili believed Cortana was aboard the Flood ship; Rtas 'Vadum could give his own troops and the UNSC only a little time to recover the AI before Voi and the surrounding area were cleansed by glassing. John-117 found the small storage device containing the AI; he entrusted to 343 Guilty Spark for repairs and they were extracted by Phantom to Shadow of Intent.

Thel 'Vadam convinced Rtas 'Vadum to exercise restraint when glassing. Thus, only an area of Africa was glassed instead of a much wider area.

Shortly after the initial skirmishes with the Flood, the Flood-infested High Charity jumped out of slipspace further out in the Sol system. Shortly after discovering the presence of the Portal at Voi, the Gravemind conducted an arcane bridging maneuver allowing it to transport the former holy city to the Ark from the vicinity of Mars rather than physically accessing the portal on Earth; the human homeworld thus escaped further Flood contamination.

Mopping up remaining Covenant forces
"Terrence Hood"

Admiral Hood and Commander Keyes joined John-117, Thel 'Vadam, and Rtas 'Vadum aboard Shadow of Intent where 343 Guilty Spark repaired Cortana's damaged storage device. The device contained only a message from the AI; it warned them that the Flood-infested High Charity was en route to Earth, but that beyond the Portal there was a solution to the Flood without firing the Halo Array.

Admiral Hood was determined to make his stand against the Flood on Earth. The Sangheili believed this to be foolish; there was little hope Earth could withstand a Flood spore, never mind a full Flood invasion, and they decided to place faith in Cortana and journey beyond the Portal. John-117 and Keyes convinced a weary Hood to allow them, and a UNSC task force to accompany the Sangheili.

The final stand Hood expected never came; the next day, High Charity and the Flood arrived in the Sol system, but instead performed a Slipspace jump from Mars orbit to Installation 00, an action that spared Earth from a second contamination. It was at the massive installation that the Flood and the remnants of the Covenant were defeated by the UNSC and Sangheili three weeks later.

With the majority of Truth's forces now bound for the Ark, the remainder of the Covenant was on Earth as they fortified themselves in Arizona, URNA. On December 3, Admiral Harper of the Fifth Fleet initiated Operation: MARSH FLASH, which eradicated clusters of Jiralhanae leadership attempting to activate an artifact here, effectively and presumably bringing an end to the global battle. Despite suffering enormous military and civilian losses, the UNSC retained control of Earth. Marines involved in mopping up Jiralhanae holdouts employed the "Rex" VISR system.

Engagements
The battle of Earth had numerous engagements across the planet. Kenya, Cleveland, Havana, and the Southewestern URNA were battlefields. Fighting also took place at Sydney, Cairo, Diego Garcia, Aranuka, the Yucatán Peninsula, and Mount Erebus.

Timeline
October 20, 2552
 * 1248 hours: Io Station station pings the encroaching Fleet of Sacred Consecration and relays this data to flag headquarters on Cairo Station.
 * At flag headquarters, Fleet Admiral Terrence Hood awards SPARTAN-117, Staff Sergeant Avery Junior Johnson and Captain Jacob Keyes medals for their efforts during the Battle of Installation 04 and subsequent actions, in the case of John-117 and Johnson, now a Sergeant Major. Miranda Keyes received her late father's medal posthumously.
 * 1412 hours: The Covenant Fleet, consisting of 2 s and 13 s exits slipspace just beyond the effective range of Earth's orbital defense platforms Fleet Admiral Joseph Harper prepares all available vessels to engage the Covenant. This order is overruled by Lord Hood, who instead orders the fleet to form a defensive perimeter around the ODP clusters.
 * 1421 hours: The Fleet of Sacred Consecration launches Type-28 Tick boarding crafts toward the orbital defense stations to plant antimatter charges. Two are destroyed in the process: Athens and Malta Stations. Cairo Station is save from the same fate by the efforts of John-117. The fleet subsequently clears the defensive grid and sends a first wave toward the planet's surface.
 * 1450 hours: John-117 uses the antimatter charge brought aboard Cairo to destroy a the Day of Jubilation, one of the two CAS-class assault carriers in the Covenant Fleet.
 * 1459 hours: The Solemn Penance, the other assault carrier the Prophet of Regret's flagship, blows through the Malta's debris field and heads straight for New Mombasa, Kenya and deploys ground forces. The First Battle of Mombasa begins.
 * 1512 hours: A number of Huragok deployed to New Mombasa are designated tier-one assets by the Office of Naval Intelligence and judged to be exposed to capture or kill. One of these, Asset RD-9743-X, would successfully be acquired by ONI in the hours to come.
 * 1557 hours: A squad of ODSTs, Alpha-Five, confirms the successful procurement of the Conduit, a Forerunner device, from the Covenant pursuant to Operation: WINDOW PANE.
 * 1602 hours: Operation: BUMRUSH is greenlit and ODSTS of the 65th Shock Troops Division are launched from the with the goal of breaching the Solemn Penance.
 * 1603 hours: Solemn Penance makes a sudden slipspace jump only hundreds of meters above the city. The assault carrier is pursued by the, which is in turn followed by two UNSC corvettes and two other frigates. This atmospheric slipspace jump creates a massive overpressure wave and electromagnetic pulse. The ODSTs' drop pods are scattered throughout the city. With Regret gone, Jiralhanae elements in the fleet suddenly turn on their Sangheili compatriots, heralding the Great Schism soon to come.
 * 1606 hours: Gunnery Sergeant Edward Buck exits his drop pod and moves toward Tayari Plaza, the location of Captain Veronica Dare's.
 * 1624 hours: All members of Alpha-Five are designated KIA and the Conduit is determined to be lost.
 * 1636 hours: UNSC Marines launch an attack on Covenant occupiers in Uplift Nature Reserve.
 * 1649 hours: The Mombasa Tether collapses. 38% of New Mombasa is occupied and controlled by the Covenant forces, now without Sangheili, at this time.
 * 1736 hours: Fierce fighting is waged along Kizingo Boulevard.
 * 1810 hours: In cooperation with the NMPD, ODSTs from Alpha-Nine set demolition charges on a bridge leading to ONI Alpha Site, in order to destroy it and slow the Covenant advance in reaching the site.
 * 1852 hours: ONI Alpha Site, the Office of Naval Intelligence's headquarters in the EAP, is destroyed by the UNSC and New Mombasa Police Department in order to deny intelligence to the enemy.
 * 1914 hours: Gunnery Sergeant Buck and Lance Corporal Kojo Agu make their way to the NMPD headquarters for pickup by an NMPD Pelican. The pelican is shot down before it can reach them and a skirmish breaks out between Alpha-Nine and Covenant air units.
 * 2141 hours: Remaining s from the Fleet of Sacred Consecration coalesce over New Mombasa.
 * 2101 hours: Alpha-Nine moves toward Kikowani Station, intending to escape the city through the MagLev train tunnels leading to Old Mombasa.
 * 2206 hours: Lance Corporal J.D., an ODST from Alpha-Nine, awakens after being knocked out after his Single Occupant Exoatmospheric Insertion Vehicle was thrust off-course in the wake of the assault carrier's slipspace jump to careen into the side of a building. He begins to search the city for others from Alpha-Nine.
 * 2215 hours: The excavation of the Excession begins.
 * 2227 hours: The Covenant controls 78% of New Mombasa.
 * 2319 hours: Asset RD-9743-X is sighted and reported by Captain Veronica Dare beneath New Mombasa in its data center.
 * 2324 hours: 94% of New Mombasa is lost to the Covenant.
 * 2359 hours: Gunnery Sergeant Edward Buck rendezvouses with Veronica Dare and Lance Corporal J.D. The Huragok, Asset RD-9743-X, is reported as secured.

October 21, 2552
 * Another Covenant fleet arrives at Earth.
 * New Mombasa is fully occupied by the Covenant and it and its surroundings are glassed in efforts to uncover the portal. Alpha-Nine extracts Asset RD-9743-X from the city safely.

October 20 through November 3, 2552
 * Spartan-II Blue Team, composed of Frederic-104, Linda-058, and William-043, is deployed on numerous zero-gee operations to repel Covenant warships over Earth. They team also participates in numerous combat missions around the world, including the Battle of Ross Island in Antarctica and an engagement with Covenant forces on the sea floor off of the Yucatan Peninsula.

November 3, 2552
 * 1420 hours: Blue Team is deployed to Cuba, where the Battle of Havana is underway.
 * 1550 hours: The Centennial Orbital Elevator is recaptured from the Covenant but destroyed by the intentional detonation of nuclear devices in close proximity to its upper reaches. Shortly thereafter, the team uses a captured Covenant Destroyer to depart for Onyx.

November 10, 2552
 * The Covenant begins to excavate and occupy built-up positions centered at Free-fire Area OZONE in Arizona, United Republic of North America, while also attempting to activate an artifact there.

November 15, 2552
 * 1725 hours: Avery Johnson interrogates Quick to Adjust, the Huragok recovered from New Mombasa, at the terminus of the Quito Space Tether.

November 17, 2552
 * The Forerunner Dreadnought arrives at Earth. Spartan 117 bails from the ship, landing in a Kenyan jungle. He is recovered by a group of Marines led by Avery Johnson.
 * The Marines, with Spartan-117, make their way to Crow's Nest, where a plan for a counterattack is devised. The base is invaded by the Covenant, and eventually destroyed by the UNSC.
 * The UNSC forces assault the Covenant-held Tsavo Highway, eventually clearing the path to the town of Voi.
 * UNSC Forces neutralize Covenant anti-air defenses in Voi. A battle group from the UNSC Home Fleet initiate the assault on the Forerunner Dreadnought, with no effect. The Portal is activated. Covenant forces flee to Installation 00 through the Portal.
 * Immediately thereafter, a Flood-controlled ship emerges from Slipspace over Voi, crashing to the town. Flood infestation starts spreading around the region. The Sangheili Fleet of Retribution, having given chase, arrives at Earth and glasses Voi as well as its surroundings.
 * A transmission from the UNSC AI Cortana is retrieved from the Flood ship. The Sangheili fleet, along with the UNSC Forward Unto Dawn go through the Portal to the Ark.
 * UNSC forces launch a counteroffensive against the Covenant at free-fire area OZONE.

November 19, 2552
 * 0630 hours: UNSC flagword LUX is declared and UEG emergency broadcast is initiated.
 * 0700 hours: A tactical nuclear deployment is carried out against multiple shielded Covenant positions.

December 3, 2552
 * Operation: MARSH FLASH sees clusters of Jiralhanae leadership eliminated.

Participants
Due to the promenince of Earth, and what had transpired prior to the battle, Earth possessed numerous UNSC assets. They clashed with several waves of Covenant forces.

Production notes
Many fans, as well as Halopedia, used to regard the Battle of Earth as two separate battles. Namely, the "First" was believed to comprise the events of Halo 2 and the "Second" was thought to cover the events of John-117's return at the beginning of Halo 3. Later sources have established that Truth's reinforcements arrived just hours after Regret fled, indicating that the "two" battles were one and the same. However, the Halo Encyclopedia (even the 2011 revised edition) lists them as two separate battles; this is one of several elements of the Encyclopedia that is seemingly lifted from this wiki.

List of appearances

 * Halo: First Strike
 * Adjunct
 * Halo 2
 * Halo Graphic Novel
 * Second Sunrise Over New Mombasa
 * Halo: Ghosts of Onyx
 * Halo: Landfall
 * Halo: Combat
 * Halo: Last One Standing
 * Halo: Uprising
 * Halo 3
 * Halo 3: ODST
 * Sadie's Story
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * Palace Hotel
 * Halo: Glasslands
 * Halo 4
 * Halo 2: Anniversary
 * Halo: New Blood
 * Hunt the Truth
 * Halo: Spartan Strike
 * Halo Mythos
 * Halo: Envoy
 * Halo: Legacy of Onyx
 * Halo: Official Spartan Field Manual