Battle for Earth

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

- Cortana

The Battle of Earth was one of the largest engagements fought between the Covenant and the United Nations Space Command, which took place on and above the planet Earth and across the Sol system from October 20 to November 17, 2552. It was one of the most important battles of the Human-Covenant War as the fate of humanity depended on the survival of their homeworld. Though the invasion took place on a global scale, the most significant conflict occurred in the East African Protectorate during the Battles of Mombasa and Voi. The battle invasion concluded when the Prophet of Truth's Forerunner Dreadnought left Earth through the Portal with the purpose of activating the Halo Array from the Ark.

Background
In the aftermath of the Fall of Reach, the UNSC began to pull its forces back to Earth, with most units assigned to defend Earth's tether cities. The Marine unit E2-BAG/1/7, among many others, was relocated from Reach to defend New Mombasa.

Discovery of Earth
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 Covenant assault fleet was discovered by the UNSC AI Cortana. A preemptive strike led by Vice Admiral Danforth Whitcomb and a SPARTAN-II strike team 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. Not being privy to Truth's information, Regret set off to uncover the artifact not realizing that Earth was the human 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

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.

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 ODST to Mombasa in SOEIVs, intending to aid Master Chief in an assault on the carrier. One squad, deploying from the and led by Captain Veronica Dare, 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 ODST 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. They 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, Prophet of Truth's Jiralhanae-led reinforcements arrived. The Jiralhanae absorbed the remainder of Regret's fleet, which had been taken over by Regret's Jiralhanae, and deployed more troops into New Mombasa. Sangheili crews and infantry were killed as part of Truth's plan to place the Jiralhanae as the Covenant's primary warrior race.

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 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.

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. Upon arrival at Earth 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 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.

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. One Flood ship 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.

Covenant separatist ships, led by Sangheili 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 in Earth's orbit. The planetoid station entered Earth's atmosphere, flew through the Portal and crashed into the Ark. Miraculously, Earth escaped contamination, as the Gravemind reserved its Flood forms for its assault on the Ark. If any Flood did manage to make landfall, they were dealt with by remaining UNSC forces by the end of the Battle of Installation 00.

Aftermath
"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 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 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 Covenant separatists.

High Charity, and the Flood also traveled to Installation 00, and there they and the remnants of the Covenant were defeated by the UNSC and Covenant separatists. Despite suffering enormous military and civilian losses, the UNSC retained control of Earth. The battle, and the Human-Covenant war, was over.

The Battle of Earth inflicted extensive infrastructural damage to the planet and Earth's population was reduced considerably. The UNSC Home Fleet was left in ruins and much of Earth's military might was destroyed. However, the defeat of the Covenant loyalists and the Flood at Installation 00 resulted in nothing less than the survival of the human species. The UNSC is currently undergoing an extensive rebuilding process.

Timeline
The following is a timeline of the battle.

October 20, 2552
 * Lord Hood awards SPARTAN-117, Sergeant Johnson and Jacob Keyes (posthumously) medals for their efforts during the Battle of Installation 04 and subsequent actions. Miranda Keyes received the medal posthumously given to her late father, Captain Keyes. The ceremony takes place on Cairo Station.
 * Io Station station picks up a communications fragment from the Prophet of Regret's fleet.
 * Regret's fleet, consisting of 2 s and 13 s exits Slipspace just beyond the range of the MAC satellites.
 * It is speculated that at this time, the warning sirens heard in the ilovebees storyline begin shortly after this Covenant sighting.
 * Fleet Admiral Harper, in charge of the Earth defense fleet, responds rapidly with an attempt at a counter attack, preparing 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 MAC clusters.
 * The Covenant launch waves of boarding craft toward the orbital defense stations. Several UNSC vessels and stations are destroyed by boarding Covenant forces.
 * The MAC platform Malta, after sending elated communications that they have repelled all Covenant boarders, is annihilated in a cataclysmic explosion. The shockwave of which is felt by the crew of the Cairo station, demonstrating just how large the detonation was. Shortly afterward the Athens MAC platform experiences the same fiery fate.
 * It is deduced that both explosions came from within each of the stations - the Covenant boarding parties had brought with them a bomb. As a result, all personnel on orbital platforms redouble their efforts against Covenant boarders.
 * The Cairo MAC platform is saved by the heroic efforts of Spartan-117, disarming (with the aid of Cortana who was acting as the platform's AI) and removing the antimatter charge from the orbital platform. The Master Chief removes the explosive device by jettisoning it, along with himself, out of a docking bay airlock. He then uses this same bomb to destroy a Covenant assault carrier that had just broken through the UNSC's defensive perimeter.
 * During a protracted naval engagement, Solemn Penance blows through the Malta's debris field and heads straight for Earth. It comes to a stop above the city of New Mombasa in the East African Protectorate.
 * From there, the first Covenant troops to ever set foot on humanity's homeworld engage in the first land engagement of the Battle of Earth.
 * UNSC forces engage the Covenant on the ground and wage a bloody street-by-street skirmish in both Old and New Mombasa.
 * After some time of ground battle and complete evacuation of Mombasa, SPARTAN-117, along with several Marines, are sent to crush the Covenant resistance in the city and infiltrate the Solemn Penance above the city, complimented by an ODST force which would be inserted from orbit directly into the assault carrier, though one squad's mission was actually separate.
 * Solemn Penance makes a sudden Slipspace jump only hundreds of meters above the city of New Mombasa. His motivations for doing so were, at the time, unknown. The assault carrier is followed by the, which, upon arrival begins the Battle of Installation 05.
 * This atmospheric Slipspace jump severely damages the City of New Mombasa. The ODSTs' drop pods are scattered around the city, most of them presumably killed by the slipspace rupture.
 * Immediately following the slipspace event, Truth's backup fleet arrives and engages UNSC forces in orbit. The Jiralhanae overtake the Sangheili on both the ground and in space while continuing to engage the UNSC. A Jiralhanae-led occupation force is also inserted into New Mombasa. The surviving UNSC and NMPD forces clash with the Covenant for control of the city.

October 21, 2552
 * Eventually, the city of New Mombasa occupied and its surroundings glassed by the Covenant, to uncover the Portal, ending the battle of Mombasa in a Covenant victory. However, the UNSC manages to extract a defecting Huragok from the city and use it to gain intel on the Covenant's goals.

October 20 through November 3, 2552
 * SPARTAN Blue Team is deployed to defend Earth during 's disappearance. They participate in numerous combat missions around the world, including the Battle of Ross Island in Antarctica.

November 3, 2552
 * SPARTAN-104, SPARTAN-058, and SPARTAN-043 partake in the Battle of Havana. Shortly thereafter, they use a captured Covenant Destroyer to depart for Onyx.
 * The Forerunner Dreadnought, with the Prophet of Truth aboard, departs High Charity for Earth.

November 8, 2552 November 17, 2552
 * The Forerunner Dreadnought arrives in the Sol system and proceeds to Earth at near-relativistic speeds.
 * The Forerunner Dreadnought arrives at Earth. Spartan 117 ejects, landing in Kenyan jungle. In the following morning, Spartan-117 is recovered by a group of Marines led by Sergeant 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 regroup along Tsavo Highway, eventually assaulting the Covenant-held 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 Loyalist 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 Covenant Separatist fleet, along with the remnants of the UNSC Home Fleet, go through the Portal to the Ark.
 * Shortly after the Covenant separatist and UNSC fleets arrive at the Ark, High Charity breaches Earth's atmosphere and enters the Portal.

UNSC

 * ODA-143 Malta Station
 * ODA-142 Cairo Station
 * ODA-144 Athens Station
 * Nassau Station
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate
 * Unidentified UNSC frigate

Covenant

 * Forerunner Dreadnought
 * Pious Inquisitor (pre-Great Schism)
 * Solemn Penance
 * Harbinger of Piety
 * Triumphant Declaration

UNSC Marine Corps

 * 2nd Shock Troops Battalion (unknown regiment)
 * 7th Shock Troops Battalion (unknown regiment)
 * 1st Platoon (unknown company and regiment)
 * 3/1 Bravo
 * A Company
 * 17th Marine Regiment
 * 77th Marine Regiment
 * E2-BAG/1/7
 * M/LAT-16
 * S/VRC-8
 * S4/BLCE/1/7
 * S4/BRT/1/7
 * Alpha Company
 * Charlie Company
 * Unidentified Shock Trooper squad

UNSC Navy

 * UNSC Home Fleet
 * Second Fleet
 * Seventh Fleet
 * Sixteenth Fleet

Covenant

 * Fleet of Furious Redemption
 * Fleet of Sacred Consecration
 * Truth's fleet

Covenant separatists

 * Fleet of Retribution

UNSC

 * Fleet Admiral Sir Terrence Hood
 * Fleet Admiral Harper
 * Unidentified Admiral
 * Cortana
 * Unidentified Navy captain
 * Captain Veronica Dare
 * Commander Richard Lash
 * Commander Miranda Keyes
 * Lieutenant Commander Julian Waters
 * Lieutenant Commander Xaing Cho
 * Lieutenant Bethany Durruno
 * Lieutenant Joe Yang
 * Lieutenant Niraj Shah
 * Lieutenant Parisa
 * Lieutenant Junior Grade SPARTAN Frederic-104
 * Master Chief Petty Officer SPARTAN John-117
 * Sergeant Major Avery Junior Johnson
 * Petty Officer Second Class SPARTAN Linda-058
 * Petty Officer Second Class SPARTAN William-043
 * Unidentified Marine officer
 * Major Pawel Czernek
 * Major Roland Huffman
 * Master Gunnery Sergeant "Gunns"
 * Gunnery Sergeant Edward Buck
 * Gunnery Sergeant Reynolds
 * Gunnery Sergeant Stacker
 * Staff Sergeant Banks
 * Sergeant Thomas Chang
 * Sergeant Twyker
 * Corporal James Dessen
 * Corporal Taylor H. Miles
 * Corporal Palmer
 * Corporal Perez
 * Corporal T. Rymann
 * Lance Corporal Kojo Agu
 * Lance Corporal "The Rookie"
 * Lance Corporal Morton
 * Lance Corporal Pineada
 * Lance Corporal T. B. Williams
 * Private First Class Michael Crespo
 * Private First Class Caio Zanato
 * Private First Class Chips Dubbo
 * Private First Class Locke
 * Private First Class Galliard
 * Private First Class Sullivan
 * Private McKenzie
 * Private Emerson
 * Private Jemison
 * Private Scottlee
 * Private S. Hartley
 * Corpsman R. Coney
 * Unidentified Corpsman

Covenant

 * High Prophet of Truth
 * High Prophet of Regret
 * Minister of Inquisition
 * Lepidus
 * Vergil

Covenant separatists

 * Arbiter Thel 'Vadam
 * Rtas 'Vadum
 * Usze ‘Taham
 * N’tho ‘Sraom

Forerunner constructs

 * 343 Guilty Spark

UNSC

 * 12-9F5
 * 957-A3
 * Echo 051
 * Kilo 023
 * Oscar 6

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