Algolis Invasion

The Algolis Invasion was a short and bloody engagement that took place and fought between the United Nations Space Command and the Covenant in the Algol system during the Human-Covenant War around early 2549. The battle on the surface of Algolis marked the formation of the Banished, a violent ex-Covenant mercenery organization and splinter faction founded by the legendary Jiralhanae warrior Atriox and his second-in-command Decimus after rebelling against the Covenant, particularly Hierarchs, which would rise dramatically to power after the empire's fragmentation in late 2552.

Background
With its own underpopulated civilian population largely removed from such efforts, the human colony world of Algolis was the home to several prototype weapon projects including HRUNTING and YGGDRASIL. These concurrent programs resulted in the creation of an armor system unmatched in the UNSC arsenal.

When the Covenant discovered Algolis circa early 2549, the particular element of the planet was believed to be the purpose of the Covenant's specific interest in this particular human colony world. As a result, they would quickly send a small but effective Covenant invasion fleet to cruelly invade the colony. The aliens' main objective was the destruction of Weapons Research Facility T12A, where the UNSC was developing highly advanced weaponry. At the time of the beginning of the Covenant assault, Algolis was largely undefended as only a lone was present during the early stage of the invasion in order to evacuate the population of Algolis.

Surprise assault on the Weapons Research Facility T12A
When the Covenant arrived, civilians immediately began to prepare their transport ships for evacuation. However, many of them were destroyed before they could even breach the planet's atmosphere. Those who survived the risky escape did so by the narrowest of margins, retreating to the lone frigate in orbit.

As the swift and cruel siege on Algolis still raged on the surface while the civilians were being evacuated by Marines, a UNSC demolitions squad nicknamed the Hades Corps, a team of combat engineers, was tasked to Weapons Research Facility T12A to enact the Cole Protocol, destroying navigation data and a Office of Naval Intelligence's prototypical combat exoskeleton and preventing them from falling into Covenant hands. The Covenant attacked the Marines in full force, breaking their defensive line and pinning down the survivors, and infiltrating heavy casualties. While Covenant forces were making their final push towards the base, all UNSC ground forces on the facility were ordered by the commander to make a full retreat but one of them disagreed as he was unwilling to abandon the Hades Corps on the planet while another said to him that the Cole Protocol was already enacted and told him to move out. In the ensuing chaos a Type-26C Banshee fired its fuel rod cannon and destroyed a spacecraft ferrying civilian colonists off the planet, killing hundreds in the process as a Phantom reinforced the Covenant ground infantry and dropped Covenant reinforcements and a Type-26 Wraith. At the time, the Hades Corps were at the Hanger 1030 and refused to leave until they would destroy the prototype of weapon systems in compliance with the Cole Protocol. However, one fearless Marine engineer, a sergeant nicknamed "Ghost" who led the squad and was initially believed to went missing or left his Marines behind, went against orders in an effort to help civilians and his Marines to escape and equipped the armor slated for destruction, hoping to redeem himself as a promise to a deceased comrade three years earlier.

Using the suit's powerful armament, Ghost first atomized the Wraith with a Type 18 Magnetic/Bayonet-style Claymore. However, his combat engineers berated him for "disobeying" the orders but Ghost said he already removed all the data and used the time left on Mark ADS I; a staggering countdown to trigger the final detonation when the system would have required a voice command. As the responsible for the Hades Corps, he said the mission cannot be jeopardized. Despite his statements, his Hades Corps comrades still order him to stop using the suit and destroy it. Ghost managed to destroy swathes of Covenant forces, savagely countering the Covenant assault and wasting most of their ground forces and vehicles such as Wraiths and aircraft, including multiple Type-26C Banshees. During the fight against Covenant forces, Ghost ordered Hades Corps to retreat, leaving him alone engaging against the Covenant forces and allowing the Marines and civilians to escape. As a Phantom supported by 2 Type-26C Banshees approached, Ghost engaged them in aerial combat, destroying the 2 Banshees and hijacking the Phantom by violently destroying it when the gunship crashed into the surface. In the ensuing battle against the ground infantry, Ghost was overwhelmed. The suit's shielding system started to fail from massive opening salvos of shots from plasma pistols, plasma rifles, and fuel rod guns wielded by Unggoy Heavies and Sangheili Minors and Zealots, and the suit has been completely disabled when a plasma grenade severed its (and Ghost's) left arm.

When the suit was damaged as Ghost struggled inside the disabled armor, he looked up at the escaping shuttles and flashed back to his female Marine's death. He admitted that the moment she died in his arms, a part of him was lost and that he had become a "ghost"—a shadow surrounded by death. A countdown on the suit's HUD finishes as Ghosts was cornered he gave a code-word activation: "Be Human". The prototype suit activated a nuclear self-destruct in the armor, killing Ghost and all remaining Covenant forces in the area. The weapons facility was consumed by the blast, depriving the Covenant of any classified data they had sought to obtain. However, after the Cole Protocol was launched, all communication was lost with UNSC ground forces, and reports of the incident are inconclusive.

Remaining Marines fell back to the lone frigate in orbit over the planet along with the surviving civilians; meanwhile the frigate would deploy an ONI contact team to verify all classified data and matériel had been purged. Ghost's commanding officer reported that the Cole Protocol has been enforced, and that all navigational data and technology prototypes have been destroyed. He redacted his previous request for Ghost's court-martial, listing him as missing in action and further stating that Ghost had demonstrated great conduct as a Marine and human being. The frigate would then move to rendezvous with the destroyer as ordered by Ghost's officer. Although the UNSC frigate assisting with evacuations of the planet was scheduled to link up with The Heart of Midlothian for an escorted Cole-compatible loop back to Earth, contact with the destroyer was never made.

Raid on The Heart of Midlothian
Shortly after the siege and eventual destruction of the Weapons Research Facility T12A, the The Heart of Midlothian dropped out of slipspace in the outlying regions of the Algol system, slingshot behind a proximal gas giant along a stream of asteroidal debris toward the planet’s surface. There, they would rendezvous with an ONI contact group deployed by the lone frigate assisting with the colony’s evacuation measures. After ensuring Algolis’ stockpile of prototype weapons were destroyed, they would leave the planet, letting it fall to the Covenant.

During the course of the mission almost as soon as The Heart of Midlothian exited slipspace, the was perfectly targeted and instantly ambushed by a small Covenant battle group of a single  as the flagship, and 4 "completely new" Covenant ships escorting it, along with a swarm of Type-28 Ticks and s. It was possible that the Covenant knew exactly where The Heart of Midlothian was going to exit inside the range of the weapons system before the shipboard AI, Mo Ye could react against the surprise attack. Two Ticks boarded the UNSC vessel and dispatched boarding parties inside the ship, where they punctured the ship in 200 different locations and killed the crew in their entirety before they could sound a general alarm save one Orbital Drop Shock Trooper, Michael Baird, who was unconscious for 23 hours since The Heart of Midlothian entered Slipspace and then when the Covenant attacked the destroyer upon its arrival near Algolis. They quickly disconnected Mo Ye. Baird was in the surgery unit during the boarding action, inadvertently saving his life.

As Mo Ye told Baird about the events that occurred while he was unconscious and Baird asked why she could not just wipe the NAV database as per the Cole Protocol, Mo Ye informed Baird that this boarding party was unlike any other due to a restriction placed on her by a "never-seen-before" Covenant species brought aboard in her disconnected state which did not allow her to willingly harm a human, systematically destroying Mo Ye's systems to prevent her from self-destructing. To allow Mo Ye to start the self-destruct sequence of The Heart of Midlothian, Mo Ye guided Baird to the bridge of Midlothian and manually boot her systems. She was able to tell him this because she had left a small piece of her coding behind to watch over Baird's procedure.

Armed with only a fire extinguisher, Baird set out for the control room but was intercepted by a small group of Covenant of four Unggoy Minors, two Kig-Yar Snipers, and one Special Operations Sangheili. He snapped the first Kig-Yar's neck by smashing down on its head with his fire extinguisher. He then used the fallen Kig-Yar's Type-51 carbine to take out the next. As the Unggoy began to disperse in fear, one accidentally ran into him. As they looked at each other, Baird noticed an energy sword running through the cowering Unggoy and himself. He looked up and noticed the leading Sangheili had run him through with his energy sword. As the Sangheili pulled away, the Unggoy fell dead and Baird was knocked unconscious.

Baird was awoken again by Mo Ye, who gave him four rumbledrugs that were similar to those used by Insurrectionists fighting Spartans on Hellas and Fumirole, slowly destroying the body, but making it totally impervious to pain and damage. Using these drugs, Baird made his way to the control room, where he encountered more of the boarding party, including the leader, who donned a decorative headdress. Baird dropped his carbine and said he would give them the coordinates of Earth if they let him escape in a lifeboat. As they began to raise their weapons at him, the Special Operations Sangheili roared at them to stop and communicated with the Huragok onboard. The Sangheili then agreed to let Baird do what he had to do.

Instead of giving the coordinates to the boarding party, Baird ordered the Huragok to reconnect Mo Ye to the ship's systems, and removed the AI's safety protocols, allowing her to destroy the ship. Despite the AI's restored access to the ship, she notifies him that she still cannot circumvent Asimov's First Law in her current state. Baird tricked the Sangheili and punches as hard as he can, breaking his hand and the alien's jaw. He begins to taunt the alien, who responds by beheading Baird with its energy sword. With all humans onboard the ship wiped out completely, Baird's sacrifice allowed Mo Ye to destroy the ship as she is no longer bound by Asimov's Three Laws and proceeds to self-destruct the ship. ​After initiating a fake countdown of four minutes, causing the Sangheili commander to order a retreat while making eye contact, Mo Ye then said "I'm kidding. There's no need for any countdown whatsoever." She proceeded to detonate the destroyer's nuclear charges, destroying The Heart of Midlothian and the Covenant battlegroup surrounding it.

Formation of the Banished
"The Executioner"

- Atriox

At some point during the Algolis Invasion on the surface of Algolis, the Covenant began to fear a revolt from the Jiralhanae Atriox, who survived in numerous large-scale battles of the Human-Covenant War such as Operation: SILENT STORM (when he was a Bloodstar Stalker) despite his improbable survival. While viewed as a legendary powerful Jiralhanae warrior in the eye of many Covenant, Atriox was in disbelief of the Great Journey and disinterested in the genocidal campaign against the humanity. Served as a cannon fodder repeatedly along with his Jiralhanae packs and continued to lose his 39 Jiralhanae brothers battle by battle, his resentment toward the Covenant and Hierarchs in particular grew.

During the ongoing Covenant siege on Algolis, Atriox participated in a siege of an Algolis city, which was ultimately devastated by the Covenant forces, allowing a to glass the city with its ventral energy projector in the night as he left angrily the now-destroyed city as many Jiralhanae forces were killed during the engagement. While Atriox returned to the Covenant planetside base that was recently established on the planet after being dropped by a Phantom's gravity lift as the only living veteran of a recent battle as the night is falling, the Sangheili Executioner in authority over the group of Jiralhanae to which he belonged was troubled by the cult of personality surrounding Atriox, speaking to the Prophet of Truth via remote communication and noted that he was never supposed to have survived this long.

Truth believed Atriox could still be a valuable tool of warfare and stated that he would only sanction his elimination if he was confirmed to be disloyal to the Covenant. After Atriox rebuked the underestimation of the humans by the Covenant as they were stronger than the Covenant realized with their abilities to kill practically all of his pack but him continually, the Executioner reported to Truth that Atriox was an even more dangerous threat than they feared when the Jiralhanae said that pure loyalty was maybe not the path to righteousness as the Covenant taught and that his Jiralhanae brothers were likely not defending the Great Journey at uselessly dying. The decision was made to have him killed, but it was agreed that it must be done so delicately in order to avoid martyrdom.

In an attempt to end his life, Atriox and other Jiralhanae were sent on one last mission against UNSC forces in a UNSC military base on the next day, carefully observed by their Sangheili masters and the Executioner hoping for his death via San'Shyuum Eyes. Most of Atriox compatriots died but he did not. After a securing victory, Atriox, who was still questioning his loyalty to the Covenant, found a wounded marine, Michael Taylor, and told him to run. As Taylor stumbled and fell while running, Atriox lazily followed and then killed him with his Type-2 gravity hammer while no malice toward the man, proclaiming his frustration and hatred for the Covenant's lies to the frightened human. Atriox faced and struck down a pious Jiralhanae who hardly challenged him for his blasphemy on the outskirts of the battlefield while in combat and desperately implore him to use reason and to see the Covenant's beliefs and strategies for what they were.

At nightfall, Atriox returned to the Covenant planetside base once again alone, met by the group of Sangheili masters commanded by his would-be Executioner. For his treason, Atriox was to be executed by the Executioner under Prophet of Truth's order. The murder of his brother at Atriox's hands on the outskirts of the battlefield was used as a pretext for this sentence. Atriox begrudgingly surrendered his gravity hammer and dropped to his knees, seemingly accepting his fate for his heretical actions. However, he did not fail to boldly and unapologetically defend his reasons for killing the one who would have done the same to him. In preparation to execute the heretic, the Executioner ignited his bloodbade. However, when the Executioner almost stabbed Atriox, the Jiralhanae caught the blade with his right hand and asked that those present watch what happened next. Rising to his feet, he stabbed his presumed and predicted Executioner through his own sword, killing him in the process as his inert body collapsed to the floor. He then challenged the other Sangheili who drew their energy swords and prepared to attack him together but at that moment other inspired loyal Jiralhanae who had been watching, including a particularly the fearsome Decimus, leaped into action, rising against their remaining Sangheili masters, killing them as Atriox remains standing still silently. After all their Sangheili masters were slaughtered by the rebellious Jiralhanae, Decimus knelt before Atriox as others howled in affirmation of their decision to follow him, and from this moment, the area of Algolis and the Covenant planetside base would be where the new splintered mercenary group that would be named as the Banished was eventually born. Atriox gloated over the dead by saying "How the righteous fall".

Although the Banished's activities on Algolis against the Covenant and the UNSC after the faction was formed are unknown, they successfully escaped the planet likely with at least one captured slipspace-capable Covenant vessel.

Aftermath
Little is known of the outcome of the battle. While the majority of Covenant ground forces were defeated, the humans suffered substantial losses and at least one city has been glassed by a shortly before the Banished's formation, and the UNSC were presumably forced to abandon Algolis altogether, letting the planet to fall to the Covenant as it would be presumably glassed eventually. However, the Covenant never acquired the technical data behind the combat exoskeleton used in the battle and, even more importantly, the Covenant failed to acquire Earth's location from the databanks on the Midlothian.

While the fate of Algolis, the frigate stationed over the planet, and its civilians remains unknown, ONI remains confident that the technical data and prototypes of HRUNTING and YGGDRASIL will remain a secret.

Banished and Covenant
"Atriox and his Banished raided Covenant resources, cutting a swath across the galaxy... Growing in strength with each attack... Gathering killers and mercenaries to his side. The Covenant had two targets in those years. Humanity and Atriox. They almost got us. But Atriox? They never came close. The whole damn Covenant couldn't contain him at the height of their power."

- Isabel tells the origin of the Banished.



Now foes of the Covenant and a target to them along with the humanity after the Banished were formed and escaped Algolis, the faction became self-reliant and started off as little more than raiders and pirates, mostly comprising Jiralhanae and several Unggoy and those who have been kidnapped from the Covenant and pressed into servitude. Atriox, now the warmaster of his faction, and his Banished began to surgically raid Covenant targets and other to scavenge for Covenant resources and gather mercenaries to their cause and grow into a formidable strength. Eventually, the UNSC was a target of those raids as well. Somewhere during the Great War or after, the Banished captured the Elegy's Lament, possibly during or after the Algolis Invasion, commanded by Atriox himself until capturing the much larger separatist CAS-class assault carrier Enduring Conviction operated by the Sangheili Shipmaster Let 'Volir who would be now defected from a large Covenant Separatist fleet to join the Banished in May 2553. Throughout the final years of the Human-Covenant War, Atriox and the Banished gained many allies and many new members in the war's aftermath from former Covenant who wished to continue living as warriors and additionally human criminals who were influenced by the Banished and may have joined.

Despite the persisting Banished raids and attacks against both the Covenant and the UNSC, the Covenant was unable to contain Atriox at the height of its power and continued to concentrate most of their forces against the UNSC and the humanity with significant deployments, targeting any remaining human colonies with the largest and most disastrous UNSC defeat of the entire war at Reach in August 2552 at the hands of a massive combined Covenant armada, and the eventual full discovery of Earth in October 2552 by the Prophet of Regret that ended the Cole Protocol and resulted in a massive prolonged global battle raging with waves of Covenant fleets. Nonetheless, the Covenant forces on Earth (other than the Prophet of Truth's focusing loyalists at the East Africa) and across the Covenant-controlled space were later left desperately organized when the Great Schism began with all Sangheili forced out from the Covenant now led by the Jiralhanae that remained loyal to the Prophets and fought each other. This would be an error from the Covenant that inadvertently served to help the UNSC save Earth from the fate of most other once-attacked human worlds, despite cataclysmic casualties on the planet when final Jiralhanae-led reinforcements from Truth arrived, and definitively ended the alien hegemony during the Battle of Installation 00 by the aid of Sangheili Fleet of Retribution. Unimpeded by the Covenant civil war, the Banished salvaged numerous Covenant former assets after its fall.

Following the Human-Covenant War, various Covenant groups of Sangheili and Jiralhanae refused to cease to massacre each other out of their hatred. A squad of the Silent Shadow led by First Blade Resa 'Azavayl was still hunting Jiralhanae that they came across to eliminate them out of their hatred for the species. When the squad boarded the Elegy's Lament and began to slaughter all Jiralhanae in the corvette unbeknownst that the ship was crewed by the Banished, Atriox, despite the Sangheili being cloaked, noticed the infiltrating assassins when they entered the bridge and stated to them that he and his loyalists were completely different from the Jiralhanae that betrayed the Sangheili nor they do care about the Sangheili-Jiralhanae feuds. He also offered a place within the Banished, where they would serve as warriors and fight under their own free will. Greatly tempted by Atriox's offer and willing to join the Banished, the squad turned against and slain their former leader Resa 'Azavayl, who refused and believed that they have the merit to face death for their "sins". Eventually, the remaining members of the Silent Shadow were happily accepted to join, offering to reward them with "blood and sport and spoils".

Again, the Banished would continue to expand even more throughout the Post-Covenant War conflicts, gaining more and more new members and occupying a number of locations such as the fully repaired Installation 00, the glassed Reach, and Installation 07 even after the Created uprising.

Ground forces

 * UNSC Navy
 * UNSC Marine Corps
 * UNSC Marine Corps of Engineers
 * Hades Corps

List of appearances

 * Halo Legends
 * Prototype
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * Midnight in the Heart of Midlothian
 * Halo Wars 2
 * Halo: Rise of Atriox
 * Halo Infinite