Battle of Mombasa

"This is the only place on Earth the Covenant decided to land. That Prophet is going to tell us why."

- Admiral Terrence Hood

The Battle of Mombasa, also known as the Battle of New Mombasa, was a large-scale engagement of the Battle for Earth, taking place in late October 2552. Over the course of the battle, Covenant forces attempted to capture the city of Mombasa, Kenya before it was quickly retaken in a matter of around one hour by the UNSC. However, after the High Prophet of Regret's retreat, the city remained occupied but now by the Prophet of Truth and his Jiralhanae loyalists. In the aftermath of the battle, the Portal to the Ark was eventually found by the Covenant, which would prove to be a major determining factor in the final outcome of the Human-Covenant War. Years after the war's end, a movement known as "Project Rebirth" emerged to endorse the eventual rebuilding of Mombasa in the aftermath of the War.

Covenant Discovery
After discovering and decrypting a Forerunner Luminary found on Meridian, the High Prophet of Regret of the Covenant was given Slipspace coordinates to a planet called "Erde-Tyrene", which was home to a Forerunner slipspace portal leading to the Ark — a facility highly important to the initiation of their "Great Journey". Unknown to Regret, Erde-Tyrene was humanity's homeworld, Earth. In his characteristic brash and ambitious manner, the Prophet of Regret, wishing to proceed with securing the Portal, took a hastily-assembled force of 15 warships to Earth. Though surprised to find not only a human presence on the planet, but a planet more fortified than any previously encountered human-held world, the High Prophet deemed his mission important enough to proceed and utilized many tactics to ensure his safe arrival on the surface. The coordinates provided by the Forerunner information indicated that his quarry was around the area of Mombasa, Kenya. Immediately after the Prophet of Truth learned of Regret's move, he sent a massive support and excavation fleet he had collected in secrecy to pick up where Regret had left off.

Mombasa
The city was relatively lightly defended, with only NMPD forces as well as some Marine units present, including the 17th Marine Regiment. Some additional military units had been transferred to the city, along with Earth's other tether cities, following the Fall of Reach to bolster their defenses in case of a Covenant invasion. These included E2-BAG/1/7 as well as some UNSC Army forces, though Lieutenant Parisa of E2-BAG/1/7 was put out of action upon deployment.

Just prior to the Covenant's attack, Sadie Endesha was on her way to Magongo to enlist in the UNSC, while photographer and journalist Benjamin Giraud was on a train heading to Old Mombasa.

Surprise Covenant invasion
"No parking, violators will be ticketed and towed!"

- The Superintendent discussing the assault carrier hovering over New Mombasa with Sadie Endesha.

On October 20, during the opening stages of the Battle for Earth, a single, the Solemn Penance, broke through the UNSC Home Fleet's defensive lines and headed towards Earth's atmosphere. The ship slipspace jumped down to the city of New Mombasa in the East African Protectorate. There, the ship came to rest over the Uplift Nature Reserve deploying infantry and mechanized support. One of the Covenant's first targets was the Mombasa Maglev train network. Despite the widespread Covenant deployment throughout Mombasa, the highest concentration of Covenant ground troops was directly below the carrier in its landing zone. Over the course of the battle, the Covenant deployed several Scarab assault platforms in both the old and new sections of Mombasa, with many of them targeting the city's space elevator. The UNSC managed to trap and destroy many of them in the narrow streets of the city.

The Covenant also sent seven Huragok, including Quick to Adjust, into Kikowani subway station, likely in search of the Forerunner structure underneath Mombasa. However, the six other Huragok instead freed Quick to Adjust from its explosive harness. While the six others were killed, Quick survived and made its way into the data center. Doctor Daniel Endesha witnessed the event, and instructed Vergil, a subroutine of the city Superintendent, to track Quick. The Covenant would find out Quick's betrayal, and send forces into the Data Center to kill Quick or prevent its defection to the UNSC.

At the time of the ship jumping down to the city, Sadie Endesha and numerous civilians had been kicked off a train in Old Mombasa. Covenant tanks that were very quickly deployed into the city, bombarded and destroyed the train in the vicinity of Makupa Station. NMPD Commissioner Kinsler and officer Mike Branley soon arrived on the scene, taking Sadie away from the crowd and headed for a police bunker outside the city. Over the course of the battle, some civilians took up arms in an attempt to defend their city, joining the Marines under command of a Marine officer. These "militias" were used as a propaganda tool by the NMPD, broadcasting their exploits over PA systems. Though a number of the stories of the militias appear to have been fabricated by Stephen at NMPDHQ, including that of "Harris 'Two-Shot' Kibaki. With the Mombasa Tether being shut down, citizens were forced to escape the city on foot or by car. The militias and armed citizens allowed for most of the people of New Mombasa to evacuate from the city to Old Mombasa using boats destined for other surrounding cities.

More UNSC Marine Corps and UNSC Army units later poured into the region after the initial attack, some of which arriving from Diego Garcia near India.

UNSC insertion
"Sergeant Avery Johnson"

- Pelican Pilots

Some time after the Covenant insertion to the city and during the civilian evacuation, the  of the Medii Battle Group descended near Mombasa to reinforce the ground troops already present. Intercepted transmission from the Covenant forces had led the UNSC to correctly believe that it was the High Prophet of Regret in command of the opposing force, making his capture their utmost priority in the right line of the originally cancelled Operation: RED FLAG. Three Pelicans, one of them with the Master Chief Petty Officer John-117 onboard, were deployed by the In Amber Clad to board the Solemn Penance hovering near the Mombasa Tether. However, before they could get near the carrier, the formation ran across a which shot down all of the Pelicans in Old Mombasa. The first was destroyed by the Scarab's main cannon, while the second, carrying an ODST squad led by Gunnery Sergeant Marcus Stacker, was shot down and crash-landed on the beach. The third Pelican, carrying Sergeant Major Avery Johnson and John-117 crashed upside-down into a building in the heart of Old Mombasa.

Outskirts
"Here, let me give him my "Welcome to Earth" gift basket."

- Walpole, an ODST about to fire on a group of Covenant at Hotel Zanzibar.

Both teams suffered few casualties from their respective crashes. The Spartan's team moved into a nearby building while Stacker's team moved up the beach to the Hotel Zanzibar and set up a command post, eliminating several Covenant units in the process. Both teams then waited in their respective locations for extraction.

After John-117 and his allies repelled several waves of Covenant including a pair of Mgalekgolo, a Pelican found the group and gave them coordinates of a landing zone. Commander Miranda Keyes ordered Johnson to regroup with the In Amber Clad so that he could coordinate further deployment of infantry and armor units while the Spartan continued on foot through the city to regroup with the second squad.

After fighting his way through multiple alleyways filled with Kig-Yar Snipers, John-117 found and assisted the ODSTs pinned down at Hotel Zanzibar. Commander Keyes sent a Warthog to the Spartan, who spearheaded a counterattack, destroying Covenant infantry, armor, and Covenant artillery emplacements on the beaches facing New Mombasa.

John-117 and his makeshift Marine unit entered a blown-out hole in a tunnel where they intercepted and destroyed a Covenant convoy, made up primarily of Type-29 Shadows that had been attempting to rendezvous with the regrouping Covenant ground forces still stationed in that sector of the city. Along the way they engaged and neutralized several barricades the Covenant had assembled to fortify the tunnel network. After the engagement in the tunnels, they advanced towards the bridge connecting Old and New Mombasa. Before the Spartan got there, the Marine unit at the bridge had already exhausted itself fighting the Scarab.

The Conduit


As the In Amber Clad's force pressed towards New Mombasa, the Covenant brought the Conduit—a Forerunner device capable of opening slipspace portals—to New Mombasa. A Spirit dropship carrying a data pad with information pertaining to the Conduit was shot down by UNSC forces. When the data pad's relevance to the Conduit was realized by the UNSC, a squad of Orbital Drop Shock Troopers was sent to recover it. Covenant forces awaiting extraction at the crashed Spirit were attacked by the ODST squad and the Sangheili Field Master carrying the data pad was killed. With the data pad, the UNSC used the information gained to pinpoint the location of the Conduit in the city. The ODST squad was directed to a Sangheili task force carrying the Conduit. After a brief engagement, the ODSTs managed to procure the Conduit from the Covenant and the device was delivered to a nearby UNSC convoy.

The Covenant responded by assaulting the convoy with waves of infantry. Though the ODST squad and several Marines attempted to defend the convoy from attacking Covenant forces, a Sangheili Field Master dropped down from his Spirit into the Elephant carrying the Conduit, retrieved the device, and escaped the engagement aboard the dropship. The ODSTs gave chase and, eventually, the Spirit was shot down. The squad located the dropship's crash site and attacked its surviving occupants. When the Field Master and his Kig-Yar bodyguards were eventually eliminated, the Conduit was reclaimed by the UNSC. The ODSTs took the Conduit aboard a Warthog and were ordered to leave the city.

Forerunner glyphs
Concurrent with the search for the Conduit, an unidentified ODST squad participated in the battle with orders to retrieve information the Covenant were interested in. Commandeering a Grizzly tank, the squad rescued marines who had recovered an emergency broadcast from a downed AV-14 Hornet, stating that its crew had captured a series of Forerunner glyphs from the Covenant. The squad then trekked their way to the site, recovered the glyphs, and escaped the city before the Solemn Penance jumped into slipspace.

Battle for New Mombasa
"Sergeant Banks"

- Corporal Perez

The Master Chief arrived at the bridge to assess the situation while Sergeant Johnson reinforced the Marines with weaponry, including a Scorpion tank. The Chief traveled across the bridge with the armored unit, clearing it of both Covenant armored and mechanized forces. These forces included Ghosts, Wraiths, Phantoms, and Banshees.

After the engagement on the bridge, UNSC forces entered New Mombasa in large numbers. They linked up with various squads of Marines as they moved through the city, eliminating Covenant forces that were setting up positions. The Master Chief's team worked their way into the Kilindini Park Cultural Center through the sewer system, and then towards the city center via Shimanzi Road and Beria Plaza, finding that the Scarab had, likewise, taken a similar path.

Once in the heart of the industrial zone near the city center, John-117's team found a Marine outpost holed in a corporate building, commanded by Staff Sergeant Banks of A Company under siege by a unit of Wraiths. The UNSC forces, with the help of John-117, destroyed the Wraiths, and secured a landing zone for reinforcements. The Pelicans then dropped a platoon of Marine infantry and a Scorpion tank.

The lumbering Scarab appeared from the other end of the plaza the Marine outpost was facing and the Scorpion tank opened fire on it, with no effect. After the Scarab destroyed the tank with its main gun, Marines opened fire on the walker, but it was unaffected and impervious to the weak rounds and climbed over their position and moved into the canals of the city. However, it soon found itself trapped inside of the walls of the canal, giving Pelicans a chance to attack it openly.

The Master Chief and A Company followed the Scarab through the canals and the Spartan boarded the walker. While the Marines provided some cover fire, John defeated the forces manning the Scarab walker. After defeating its command crew, he managed to destroy the Scarab from the inside. All Covenant forces soon began retreating to Regret's carrier. The Master Chief was extracted by Sergeant Johnson's Pelican and taken back to In Amber Clad along with the remaining members of A Company.

Regret's withdrawal
"Remi"

- Miranda Keyes

The Pelicans carrying Spartan-117 and the Marines entered the In Amber Clad, just as the carrier was preparing to flee. Fleet Admiral Terrence Hood was hesitant to let In Amber Clad engage Regret's assault carrier, still above Mombasa and beside the Mombasa space elevator. He instead opted to call in two heavier vessels to intercept the carrier if it returned to space. However, when the carrier initiated its slipspace drive, preparing to jump while still in the atmosphere, Hood gave the ship the green light to give chase. The, , and , and the followed in the wake of the slipspace jump, with the latter ship losing contact with its companions in the slipstream.

Just before the carrier jumped, remaining ships of the UNSC Home Fleet deployed dozens of SOEIVs down to the city in an effort to infiltrate the carrier, only to be caught by the EMP blast in mid-flight, destroying their navigational and safety systems, plunging them and their Orbital Drop Shock Trooper occupants to almost certain death. It is likely that only one squad survived, having changed their course away from the carrier at the last moment. Many of the city's buildings were heavily damaged but remained standing, including the Mombasa Tether. The rupture also created a large crater in the mainland, north of New Mombasa, revealing a section of the Forerunner portal. This event would later become referred to as the New Mombasa Slipspace Event, and would lead to the reactivation of the old NATO Outpost C9.

The ODSTs in possession of the Conduit were escaping the city as the nearby Solemn Penance entered slipstream space over Mombasa. When the resulting slipspace rupture engulfed the city, the ODSTs were killed and the Conduit was believed to have been destroyed as well. However, the Conduit entered slipspace to save itself from destruction and arrived at Installation 03.

After the Slipspace Event
"We need to get above this crap, link up with the bee-net. One of our drones must have seen where they hit."

- Edward Buck to Kojo Agu after meeting in Tayari Plaza.

Large numbers of Covenant troops remained in the city even after Regret's withdrawal. While most of Regret's troops evacuated into the carrier, there was still a significant Covenant presence both on the ground and in orbit. Moments after Regret jumped, the Prophet of Truth seized the control of the battle and assumed the command of what remained within Regret's initial fleet while a large support and excavation fleet of Jiralhanae-led Covenant reinforcements was en route to Earth. The remaining Jiralhanae from Regret's forces were simultaneously given orders to execute the Sangheili forces on the ground and in orbit. This was a part of the Prophet of Truth's personal scheme for the Covenant, which would come to its conclusion two weeks later when the Sangheili were officially removed from their positions as the main warrior caste of the Covenant.

The Covenant forces were met by a sizeable number of UNSC Marines and NMPD forces that remained in the city. The human forces organized an effective resistance, and fought for control of the city throughout the remainder of the day. The city's Urban Infrastructure AI Superintendent also had a vital role in the defense of the city.

Knocked off their course by the slipspace rupture, two SOEIVs made rough landings: Gunnery Sergeant Edward Buck's pod in Lumumba, and Captain Veronica Dare's in nearby Tayari Plaza. At this point in the battle, large groups of Jiralhanae led forces were being deployed into the city. Buck fought his way to Tayari Plaza to help Dare, but upon making it to her pod, he discovered that the Captain had disappeared. Meeting with another of his squad mates and with no idea what his objective was now, Buck took the decision to reunite with his squad and then extract them from the city as fast as possible.

Assault on the Covenant landing zone
"Colonel"

- Taylor Miles

Around thirty minutes after the slipspace event, unmanned F-99 UCAVs were sent to the city to maintain air supremacy over the Phantoms and Banshees. UNSC forces began to regroup, following the orders of a Marine colonel. The Marines were ordered to regroup at the colonel's position near the landing zone, and take control of Regret's carrier's former landing zone in the Uplift Nature Reserve in an effort to seize an unidentified enemy asset, later revealed to be groups of Huragok. Marines at the Uplift Reserve, led by a surviving ODST, managed to break through Covenant defenses along the way to the landing zone. At this point, the Mombasa Tether, already damaged by the jump, collapsed, with miles of debris from the tether scattered across East Africa. The collapse also killed the colonel, who, in his final moments, ordered Marines to evacuate from the park. With the colonel dead and the Covenant transporting all Huragok away from the park, the UNSC forces gained little advantages from their efforts in the park.

Fallback to ONI Alpha Site
"Marine"

- Jiralhanae

After the UNSC reclaimed the Covenant landing zone in Uplift Reserve, defending the Office of Naval Intelligence's local headquarters became the top priority. Ninety minutes after the slipspace event, Marines began falling back to the building as advancing Covenant Wraith convoys prepared to lay siege to Alpha Site. Kizingo Boulevard in Sector 4 became an important location where UNSC forces have set up stationary M68 Gauss cannons to defend the entrance to the rally point at Sector 10, which leads into Alpha Site. Marines managed to regroup at Sector 10 before falling back further into the ONI complex.

Within the ONI compound, the Marines and the NMPD forces destroyed the bridge leading to the base, in hopes of slowing down the advancing Covenant forces. This did not, however, stop the incoming dropships, but slowed the advance. The human forces fell back to the base's courtyard, which they defended against waves of Covenant attackers, before falling back into the interior of the main building. Again, they fended off multiple waves of Covenant. NMPD forces then planted explosives inside the complex, to destroy it in order to prevent the Covenant from accessing the Superintendent's data facility deep under the building. The only survivors of the siege were two ODSTs from Alpha-Nine, Michael Crespo and Taylor Miles, who evacuated from the roof, where they were picked up by an NMPD Pelican dropship. Once on board, they detonated the explosives and watched as the ONI building was completely destroyed. Six hours later, the building was still burning from the explosions. At the time, Crespo and Miles were unaware that destroying the building had alerted a newly-constructed Yanme'e hive beneath the building in the Superintendent's data facility, making it much more difficult for UNSC forces to reach the data core later on.

Skirmish at NMPD Headquarters
While the Alpha Site was destroyed, Edward Buck and his squad's sniper, Kojo Agu, made their way to the top floors of the NMPD headquarters building, where they were to be picked up by Pelican with two other ODSTs already onboard. However, the dropship was shot down before landing, and it crashed on another rooftop, killing the pilot on impact. Buck and Agu fought their way across the rooftops, and eventually reached the crash site, where they fought off waves of attacking Covenant using heavy weapons from the Pelican. Finally, a Jiralhanae Chieftain dropped off from a Phantom, killed an NMPD officer and severely wounded Agu. The squad managed to kill the Chieftain, after which they decided to evacuate through the train tunnels which led into Old Mombasa.

Nightfall
"Michael Crespo"

- Edward Buck

By nightfall, nearly all human forces in the city had either been evacuated or destroyed. With Covenant forces controlling the city, remaining Covenant cruisers left by the Prophet of Regret began excavating the area around the crater created by the slipspace rupture. Among the few human survivors were the members of Alpha-Nine, who arrived at Kikowani Station near the city's northeastern seawall, only to realize that the station, as well as its surroundings had been flooded by water, making escape through train tunnels impossible. The squad decided to hijack a Phantom dropship, in which they succeeded. Buck escorted the rest of the squad through the flooded sections of the city in a Banshee. The area was filled with Covenant forces, including a Scarab. After destroying the Scarab, they managed to fly out of the city, when Buck suddenly realized he knew where Captain Dare was and decided to go back to find her, inside the Superintendent's data center.

Around the same time, a lone ODST from Alpha-Nine, Lance Corporal J.D. "Rookie", thought dead by the rest of the squad, woke up in his pod, on the edge of a rooftop in Mbaraki. The city was already occupied by the Covenant, with no UNSC resistance left. The Superintendent aided the Rookie to survive in the city and look for clues for what happened to his squad. After wandering around the city for a while, the Rookie received a distress message from Dare, who was inside the Superintendent's data facility deep under the city. He made his way to a subway entrance, and descended down an elevator shaft, to Sublevel 7 of the data center. At this point, the underground tunnels had become infested with Yanme'e, who had built massive hives in the area.

Extracting the asset
"Veronica Dare"

- Edward Buck

Eventually, the Rookie managed to meet up with Dare inside the Superintendent's Data Center. The two fought through the Yanme'e hive in sublevel 10, causing the Yanme'e to alert the Jiralhanae, who sent more reinforcements to the Data Center. Inside, Dare and Rookie discovered the Huragok Quick to Adjust, who had combined the Superintendent, namely its Vergil subroutine, with itself. As Quick disconnected from the core, the AI shut itself down, as all of its data had been transferred into the creature. At this point, Buck arrived into the complex and the ODSTs escaped back to the surface through the Covenant-occupied tunnels, while protecting the critically important Huragok.

The next day on the morning of October 21, planned reinforcements of the enormous Jiralhanae-led Covenant support and excavation fleet from the Prophet of Truth began to exit slipspace above Mombasa and across its surrounding areas, ensuring the full secure of large portions of the Africa from the UNSC and reinforcing excavation measures by the remaining forces of the Fleet of Sacred Consecration despite Covenant's lack of intel on the nature of the gateway Portal complex to the Ark.

During the final hours of the day, the area was now full of arriving Covenant capital ships. More Scarabs have been deployed to the city, and a massive air force of Banshees were deployed to the crater. Buck, Dare and the Rookie made their way to the surface, through a Covenant outpost in Sector 1, and eventually took an elevator to the city's Waterfront Highway. They then pushed through the highway and made a stand at the entrance to Uplift Reserve. The Phantom captured by the rest of the squad arrived and picked them up, and they made it out just as an assault carrier appeared from slipspace and glassed the area.

Immediately after the Covenant occupation of Mombasa was achieved, the combined Covenant fleet gathered over Kenya continues to uncover the Forerunner structure which activates a portal to the Ark. When the Covenant fleet was prolongedly glassing the majority of the East Africa, millions would have persished over course of the excavation effort before it ended at the final stages of the Battle of Kenya.

New Mombasa and Earth
"Before 2552, there was no way anything like that could happen on Earth. On one of those distant planets in the outer colonies, maybe. But an attack on Earth? Couldn't happen. Until it did. It's called glassing. Covenant warships rain plasma down on a planet until everything and everyone on the surface melts. Usually, it's complete world destruction. Earth only got a taste. The prolonged orbital bombardment destroyed East Africa, killing millions before it ended. None of us were safe anymore."

- Benjamin Giraud

The UNSC would not discover the actual purpose of the Covenant's arrival on Earth until two weeks after the Battle of Installation 05; most of the information was presumably received from the Huragok that had absorbed Vergil's data. By this point, the Prophet of Truth had already arrived in Sol System on the Forerunner Dreadnought, along with many remnants of the diminishing Covenant such as the remainder of Covenant survivors of the Battle of Installation 05 with him. The UNSC would assume the Forerunner structure to be the "Ark" until its activation during the Battle of Voi on November 17, 2552.

The remnants of New Mombasa were liberated after Truth's fleet retreated to the Ark and were subsequently defeated, with Operation: MARSH FLASH beginning as part of the URNA Southwest Campaign.

Parts of Mombasa, like Haller Street, survived the battle. Haller Street and other areas had received some revitalization after Project Rebirth investment and UNSC interest in the Portal at Voi. At some point through Project Rebirt, plans had been created to build the United Nations Space Command Memorial Park in the city.

Some of the refugees of the battle ended up on the planet Oban.

Solemn Penance and UNSC In Amber Clad
The Solemn Penance would arrive at Installation 05 on November 3, the Prophet of Regret having learned of the ring's location from the Luminary on Meridian. The assault carrier was followed by In Amber Clad, who deployed a contingent of ODSTs led by John-117 on a mission to capture or kill the Prophet, an objective they would accomplish. The Coral Sea, Dusk and Redoubtable all arrived as well, but at different times. The last ship to arrive, the Dusk, appeared in time to witness the outbreak of the Great Schism.

Alpha-Nine, Vergil, and Sadie Endesha
Alpha-Nine was assigned to guard Quick to Adjust. Eventually, the Huragok was interrogated by Avery Johnson on Quito Terminus, where Quick to Adjust and Vergil confirmed that the Covenant at New Mombasa were searching for the "Ark", or as revealed upon its activation, the Portal to the Ark. A transcript of the interrogation of Vergil was given to Terrence Hood in a document titled "Vergil".

A timeline of events in the Battle of Mombasa and the CSV of Edward Buck were compiled for Margaret Parangosky by Black Box titled "First Twelve Hours".

Forerunner glyphs and the Conduit
In the summer of 2557, nearly five years after the battle, the Forerunner glyphs recovered by several ODSTs in the city were finally decoded, pointing to a region on Gamma Halo containing an unidentified Forerunner machine.

October 20, 2552

 * 1459 hours: The Solemn Penance targets New Mombasa. The carrier slipspace ruptured down to the city, and came to rest over the Uplift Nature Reserve.
 * Between 1459 and 1603 hours: Solemn Penance drifts towards the New Mombasa Orbital Elevator. John-117 deployed to Old Mombasa and fights into the heart of New Mombasa. Sadie Endesha teams up with Mike Branley and struggles to reach the Mombasa city center and to find her dad Daniel Endesha.
 * 1512 hours: A T1 asset is exposed to capture or kill.
 * 1557 hours: Alpha-Five confirms procurement of the Conduit.
 * 1602 hours: ODST units are dropped from as part of Operation: BUMRUSH.
 * 1603 hours: Solemn Penance departs from the city via slipspace. follows. Alpha-Nine squad members are scattered by the shockwave. Alpha-Five in possession of the Conduit attempt to flee the blast. The blast destroys much of the Superintendent's electronics. Edward Buck crash lands in Lumumba and attempts to meet Veronica Dare at Tayari Plaza. However, he ends up with Kojo Agu.
 * 1624 hours: Alpha-Five is designated KIA and the Conduit is lost.
 * 1632 hours: Taylor Miles exits pod in the Uplift Reserve and links up with UNSC forces to secure landing zone. UNSC conducts F-99 Wombat flyovers of the Reserve.
 * 1649 hours: The Orbital Elevator collapses. Covenant occupy roughly 38% of the city.
 * 1732 hours: Marines begin retreating and grouping up at a rally point at ONI Alpha Site. Michael Crespo links up with retreating UNSC forces on Kizingo Boulevard.
 * 1810 hours: Marines and remaining NMPD officers retreat into the inner walls of the ONI Alpha Site. Road bridge leading to it destroyed. Covenant begin dropping forces off by Phantom.
 * 1852 hours: Alpha Site is destroyed. Covenant occupy 51% of the city. Michael Crespo and Taylor Miles were extracted to NMPD headquarters.
 * 1914 hours: Michael Crespo and Taylor Miles are shot down over a Covenant occupied NMPD HQ. Kojo Agu and Edward Buck rescue and link up with them.
 * 2101 hours: Michael Crespo, Taylor Miles, an injured Kojo Agu, and Edward Buck proceed into Kikowani and find transport out of the district.
 * 2141 hours: Remaining Covenant cruisers begin to group up at Mombasa.
 * 2206 hours: The Rookie wakes up in his pod. He begins to search for his squad mates by looking for clues. The Superintendent assists. The Rookie meets Dare at the New Mombasa Data Center.
 * 2215 hours: Covenant begin excavating the hole the Solemn Penance tore into Old Mombasa.
 * 2227 hours: Covenant occupation is 78%.
 * 2319 hours: Veronica Dare reports that she has spotted Vergil.
 * 2319 hours: The Rookie, Dare and Buck escort Vergil along the New Mombasa Waterfront Highway.
 * 2324 hours: Covenant occupation is 94%.
 * 2359 hours: Vergil is secured.

October 21, 2552

 * A much larger Covenant fleet from the Prophet of Truth began to arrive in-system above Mombasa in order to reinforces the excavation efforts. Buck, Dare, and the Rookie defend Vergil 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 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 glassed by the combined excavation fleet.

Units

 * UNSC Marine Corps
 * Orbital Drop Shock Trooper
 * 105th Shock Troops Division
 * 7th Shock Troops Battalion
 * 65th Shock Troops Division
 * Alpha-Nine
 * Alpha-Five
 * Unidentified ODST squad
 * A Company
 * Second Platoon
 * E2-BAG/1/7
 * UNSC Navy
 * Home Fleet
 * Fifth Fleet
 * Medii Battle Group

Trivia

 * The multiplayer levels Turf, Terminal, District in Halo 2 and Longshore in Halo 3 take place during the Battle of Mombasa. The Halo 2 level Tombstone apparently takes place late in the battle, (roughly concurrent with Halo 3: ODST) as the city is largely in ruins.
 * Sadie's Story depicts Regret's assault carrier arriving in the city via slipspace. The carrier's descent to the atmosphere is never shown in any other source, but it may have made a short, pinpoint jump to get away from the UNSC forces.
 * Judging by the timeline, New Mombasa was supposed to be over a thousand kilometers further south than Old Mombasa due to geographical latitude placement. This could be an oversight by Bungie due to geographical emplacement; by 1900 hours, near the equator line, the sun has already set, while on the level NMPD HQ, at 1936 hours the sun is still setting.

List of appearances

 * Halo: First Strike
 * Petra
 * Halo 2
 * Halo Graphic Novel
 * Second Sunrise Over New Mombasa
 * Halo: Ghosts of Onyx
 * Halo 3
 * Halo 3: ODST
 * Sadie's Story
 * Halo Legends
 * Origins
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * Palace Hotel
 * Halo: Reach
 * Halo 4
 * Halo 2: Anniversary
 * Halo: New Blood
 * Hunt the Truth
 * Halo: Spartan Strike
 * Halo Mythos
 * Halo: Envoy
 * Halo: Bad Blood
 * Halo Infinite: Memory Agent