John-117

Looking for the UNSC Navy rank Master Chief Petty Officer, the Halo 3 level Sierra 117, or the Halo Wars character John Forge?

"Wake me... when you need me."

- John-117 to Cortana

"You are the culmination of a thousand lifetimes of planning."

- The Librarian to John-117

Master Chief Petty Officer John-117 is a SPARTAN-II commando of the UNSC Naval Special Warfare Command. He became one of the most important heroes of the UNSC during the Human-Covenant war. With nearly 30 years of active duty, he is one of the most decorated war veterans in the United Nations Space Command, and has earned every known medal in the UNSC except the Prisoner of War Medallion.

He is the protagonist and main playable character in the Halo trilogy and the Reclaimer trilogy. In the games, John is only ever referred to by name once in the first trilogy, by Cortana, in the ending cutscene of Halo 3, before the credits. He is referred to universally by humans simply as the "Master Chief", "Chief" for short and "Sierra-117". The Covenant are aware of the power of the Spartans, and refer to the Master Chief as "the Demon", although, after the Great Schism, Thel 'Vadam and Rtas 'Vadum called him Spartan. John is referred to as "Reclaimer" by both Forerunner enemies and their AI constructs, although this seems to be a universal title given to all humans, rather than specifically referring to John-117.

Childhood and Spartan training
"They let me pick. Did I ever tell you that? Choose whichever Spartan I wanted. You know me. I did my research. Watched as you became the soldier we needed you to be. Like the others, you were strong and swift and brave. A natural leader. But you had something they didn't. Something no one saw, but me. Can you guess...? Luck. Was I wrong?"

- Cortana Born in about 2511, John lived with his mother and father in Elysium city, on the colony world of Eridanus II. He attended the Elysium city Primary Education Facility Number 119. As a child, John had brown hair, freckles, and a small gap between his front teeth. In a dream during cryo-sleep aboard the, John recalled that his mother was "kind and smelled of soap", and that she had "large eyes, a straight nose and full lips." The would-be UNSC Marine Lieutenant Parisa was a childhood friend of John's. John once saved her from drowning at Lake Gusev, after which John promised to marry her and keep her safe. A photo of the two was also taken by Parisa's father soon after, and would be kept as a memory by Parisa long after she thought John had passed away.

At the age of six, he was identified by Dr. Catherine Halsey as one of 150 preliminary candidates for the SPARTAN-II Program. John was an ideal physical and mental candidate, standing a head taller than the majority of his schoolmates, having greater physical proportions, possessing greater strength, exhibiting superior reflexes, and having an aggressive drive for success. When Dr. Halsey and Lieutenant Jacob Keyes visited Eridanus II in 2517 to study him, they were impressed with his intellect and luck. In a final test of his viability as a candidate, he was asked to determine which side an old coin would land on. He watched the coin as it flew in the air and caught it before it could land, correctly stating which side was face-up, which was the side of the eagle. John was the first candidate Dr. Halsey and Lieutenant Keyes studied. Later that same year, John and 74 other six-year-old children were "conscripted": they were covertly kidnapped from their homes and replaced with flash clones, all of which would later die of natural causes to cover up the kidnappings. John, along with the other candidates, was taken to the planet of Reach. Dr. Halsey informed them of the SPARTAN-II Program and how they would be "the protectors of Earth and all her colonies." The next morning John discovered his service tag, stitched into his training uniform, and his new name: John-117.

John began a new life, training with other Spartans under Chief Petty Officer Franklin Mendez. For eight years he learned history, military strategy, weapons, and was given physical fitness training. Early on, he bonded with Kelly and Sam, who would become two of the few close friends he would ever have.

"He is neither the smartest nor the fastest nor the strongest of the Spartans. But he is the bravest - and quite possibly the luckiest. And in my opinion, he is the best."

- Dr. Catherine Halsey to Cortana

During his training, John quickly proved himself to be one of the program's top candidates. Both Dr. Halsey and Chief Mendez identified him as one of four emerging leaders within the Spartan-II group, along with Kurt-051, Jerome-092, and Frederic-104. Dr. Halsey expressed her belief most strongly in John as having the skills and natural ability to lead the entire Spartan-II group. However, Mendez disagreed, instead believing Kurt would fulfill that role.

When the Spartans were eight years old, they were sent on a training mission in which they were dropped over a forest located deep in one of Reach's snow-filled mountain ranges and expected to get safely to their extraction Pelican dropship. The children also had instructions to leave the last child arriving behind, or the punishment would be painful; John-117 knew, however, that he could not do that. After telling the Spartans where to meet, the Spartans looked to him as their leader, a role he was initially surprised to be given, but eventually accepted. When the group came upon the Pelican, it was guarded by armed men. Those men were actually UNSC Marines, but were not in uniform, thus leading the Spartans to mistake for a hostile threat. John showed early acumen in critical thinking and tactics, not wishing to take for granted that guards would be friendly toward them. He came up with a plan to take the men down, capture the dropship, and ensure the safe extraction of every team member, as he made sure he was the last person aboard. To do this he ended up hijacking the dropship with the help of Déjà, and beat down the men with stones, causing severe injuries among the Marines. Chief Mendez was not visibly pleased, as John had attacked his Marines and no one had been left behind. But both Mendez and Halsey recognized John's initiative, and promoted him to squad leader. After this, despite other Spartans rising in rank and at least a couple rising to lead their own teams, he remained the de facto leader of the Spartans as a whole.

John's leadership skills were correctly observed, as the result from their mission clearly solidified his role as the overall leader of the Spartan-IIs. He also became the established leader of the Spartan-II's Blue Team.



At the age of fourteen, John underwent the dangerous SPARTAN-II augmentation procedures. These procedures caused 30 of the Spartan trainees to die, and 12 to become physically disabled. John was one of 33 Spartans who made it through the process unscathed, while the rest who could still operate were moved to positions in the Office of Naval Intelligence. At only fourteen years old, it is said that John had a body of an eighteen-year old Olympic athlete; the augmentation process gave the Spartans faster reflexes, greater strength, enhanced eyesight, and made their bones nearly unbreakable. Following their augmentation procedures, John and the other Spartans were transferred to the Atlas in order to recover in a microgravity environment. During his first visit to the Atlas' gym, John was confronted by four ODSTs, whose sergeant then ordered the five of them into the boxing ring. In the ensuing fight, John killed two of the ODSTs, and left the others severely injured, an incident which quickly blossomed into major resentment for the whole SPARTAN program throughout the Marine Corps. According to Major Antonio Silva, this incident was orchestrated by the "people who invented the Chief" in order to test the Spartans' augmentations.

Early military career


John's first mission was against rebels in the asteroid belt of the Eridanus system, where his home world was located. He was shot in the side by live ammunition while leading his squad to capture rebel leader Colonel Robert Watts, without heavily injuring him. The mission casualty list is 11 dead rebel soldiers and an un-known number of rebel civilians. He received a Purple Heart after this mission for taking a round in the side.

Three months after the Eridanus mission, John and his Spartans were briefed on the massacre that took place on Harvest shortly after first contact with the Covenant. A short time later, the, under the command of Captain Wallace, brought the Spartans and Dr. Halsey to the Damascus Testing Facility at Chi Ceti, where they received the MJOLNIR Mark IV Powered Assault Armor. When a Covenant ship, the Unrelenting, attacked the Commonwealth, John and the SPARTAN-IIs took part in their first battle with the Covenant. The Spartans used thrusters to launch from a Pelican dropship. Each Spartan carried an ANVIL-II Air-to-Surface Missile to destroy the Covenant ship. Only two other Spartans made it to the ship with John: Samuel-034 and Kelly-087. They entered the ship through a hole in its hull, caused by a MAC round from the Commonwealth. They succeeded in completing the mission and destroyed the Covenant ship, but due to a breach in Sam's armor, caused by retaliation fire from Covenant forces, he was unable to leave the Covenant ship. Volunteering to stay behind and ensure the destruction of the enemy vessel, Sam was killed in the ensuing explosion. John was profoundly affected by the loss of his first and closest friend. This victory proved to John that the Covenant were not invincible, but could only be defeated at a high cost in lives. John and the remaining Spartans would fight the Covenant for the next 27 years, employing their MJOLNIR armor to its fullest capability.

In 2526, The Covenant attacked the Corbulo Academy of Military Science which sparked the Battle of Circinius IV, John protected the cadets and fought off Covenant forces while waiting for evacuation by Kelly-087 and Frederic-104. This is where he would first meet Commander Thomas Lasky who was a young cadet at the time.



In 2544, John, along with Fred-104, Kelly-087, Solomon-069 and Arthur-079, was part of a mission to rescue Dr. Catherine Halsey from a Covenant fleet. The team utilized OF92/EVA "Booster Frame" fighters, which were designed for ship boarding actions, and infiltrated a Covenant Assault Carrier. Aboard the Assault Carrier, John encountered Major Domo Thel 'Lodamee, who challenged John to an Energy Sword duel. Thel was forced out of the duel when his Fleetmaster separated the lower section of the Assault Carrier to kill the Spartan, pulling him back into the upper section. Both combatants were left unscathed. The Spartans completed the mission and rescued Dr. Halsey, but Arthur and Solomon were killed. John was deeply saddened by his teammates' deaths, vowed to become stronger, and to never allow such a loss happen again.

John served in over 200 missions against the Covenant, including the Harvest Campaign, the Battle of Jericho VII, where he and a handful of Spartans destroyed a force of over a thousand Grunts, and the Battle of Sigma Octanus IV, in which John and his Blue Team detonated a HAVOK Nuclear Warhead to clear Covenant forces from the city of Côte d'Azur. By summer of 2552, he had received every medal awarded by the UNSC except the Prisoner of War Medallion, the reason being that Covenant forces do not take prisoners, and John would not allow himself or any other SPARTAN-II to be captured by the enemy.

Fall of Reach
The Fall of Reach, though brief, was of great significance for John. Here he received the MJOLNIR Mark V Powered Assault Armor, which improved his strength and reaction time more effectively than his older Mark IV suit. He was also introduced to and partnered with the AI Cortana, who would become a close friend and ally to him. In the first test of their partnership, the two were put through a practically suicidal test in an attempt by Colonel Ackerson to get rid of John. John refused to cheat the test and was determined to win it by Ackerson's rules. Despite nearly being killed, Cortana and John's teamwork had them pass the test in an early show of the incredible partnership the two would come to develop. After Reach came under attack by a massive Covenant armada, the majority of the Spartans, led by Fred S-104, went to the planet's surface to protect the Orbital Defense Generators which powered the planet's twenty Orbital Defense Platforms. John, with Linda and James-005, were sent to Reach Station Gamma to destroy an unsecured NAV database on board the. If the Covenant obtained the database, they would discover the location of every human world, including Earth; the location of Earth by then was still a closely guarded secret. The NAV database was destroyed, but Linda and James were ambushed by Covenant Sangheili; James was lost in space, and Linda was critically wounded. John saved four other Marines on the station, including Staff Sergeant Avery Johnson. The team returned to the and was placed into cryo-sleep as the ship landed on, then fled Reach and, following the Cole Protocol, jumped into Slipspace with coordinates deduced by Cortana from constellation data retrieved earlier, in hopes of leading the Covenant away from Earth.

Installation 04
Once the ship had arrived safely at Installation 04, it emerged that the UNSC  had been followed through Slipspace by around a dozen Covenant ships, who ultimately engaged the Autumn and sent several boarding parties to board the ship. Captain Jacob Keyes ordered John to be woken from cryosleep, and tasked him with ensuring the escape of Cortana (who was the ship's AI), while he crash-landed the Pillar of Autumn on the unidentified ring.

John escaped the Pillar of Autumn on a life pod, and rallied Marines to fight against Covenant forces stationed on the ring. Cortana found out that Captain Keyes had been captured and was held prisoner on the CCS Truth and Reconciliation, by way of hacking into the Covenant battlenet. John joined the strike team that was sent to rescue Captain Keyes, where he learned that "Halo" was a super weapon. The Captain gave John new orders, to locate the map room that pinpointed the location of Halo's Control Center. When the Chief was finished, he was dropped off in the first of three snowy chasms leading towards the Control Room. During the long trek, he encountered Fire Team Zulu and they assisted him in securing the first and second chasms.

Initially, fighting on Halo was between UNSC and Covenant forces, but after Captain Keyes unwittingly released an ancient parasite, the majority of both forces were infected, and the fighting shifted to combating the new enemy.

Flood infestation of Installation 04
"Do you have any idea what that bastard almost made you do?"

- Cortana

"Yes... activate Halo's defenses, and destroy the Flood, which is why we brought the Index to the Control Center."

- John-117

John-117 was sent out by Installation 04's Monitor, 343 Guilty Spark, to retrieve the Index, an activation device for the Halo ring that the Master Chief is led to believe would destroy all Flood forms within a large radius. Upon John's return to Halo's Control Room, Cortana revealed that Halo's true purpose is to destroy all sentient life forms in the galaxy to starve the Flood, not to kill the Flood themselves. John was then forced to disrupt Halo's firing system by disabling Halo's Phase Pulse Generator in order to delay the Monitor's plan.

John soon joined the three-sided combat among the Covenant, the Flood and the Forerunners' Sentinels. Soon after, he tried to rescue Captain Keyes, but was too late. Captain Keyes had been transformed into a Proto-Gravemind Flood form. After infiltrating the Truth and Reconciliation, the Chief managed to retrieve the Captain's neural implants, which he used to activate the Pillar of Autumn's self-destruct sequence. After the sequence was aborted by 343 Guilty Spark, he proceeds to manually overload the fusion reactors, which would subsequently destroy both the Pillar of Autumn and Installation 04.

After successfully destroying the fusion reactors on the Pillar of Autumn, John-117 used a Warthog to reach the extraction point where Pelican Echo 419 would pick him up. John-117 reached the extraction point, only to witness the Pelican crashing into the Autumn's hull after being shot down by a pair of Banshees. The Chief quickly diverts his escape route towards the ship's hangar bay, which housed a Longsword fighter. Only a handful of UNSC forces survived, including Lieutenant Elias Haverson, Corporal Locklear, Warrant Officer Sheila Polaski, then-Staff Sergeant Avery Johnson, Private First Class Chips Dubbo, and then-Staff Sergeant Pete Stacker.

Journey to Earth and Operation: FIRST STRIKE
After the destruction of Alpha Halo, Cortana and the Master Chief fled through space in the Longsword they had escaped in. He discovered three cryotubes floating nearby, one containing Linda-058, and retrieved them. Soon after, the Covenant's flagship Ascendant Justice came into the system along with a few cruisers, some of which had possibly escaped Halo's destruction and called the flagship to Threshold. A nearby Pelican dropship, which had docked on an asteroid floating among Halo's debris field,fired at the cruiser to distract it. After a successful escape from the Covenant battle group, John linked the two vessels and brought its passengers aboard the Longsword. The crew of the Pelican then helped John in capturing the Ascendant Justice; the human survivors then traveled to Reach to look for surviving Spartans. John eventually located some of his fellow SPARTAN-IIs on Reach, along with Vice Admiral Danforth Whitcomb and Dr. Catherine Halsey. They returned to the ship and linked it with the UNSC frigate. They began to travel toward Earth and soon discovered a base belonging to the Eridanus Rebels, led by Governor Jacob Jiles.

After receiving some repairs, Dr Catherine Halsey surreptitiously leaves with Kelly-087 to an unknown location aboard Governor Jacob Jiles personal ship, at the time docked with the /Ascendant Justice. The remaining UNSC forces were forced to abandon the rebels in the face of a Covenant assault, and made their way toward the Covenant refit-and-repair station, Unyielding Hierophant, where an enormous fleet was poised to invade Earth. Just before the slipspace jump, Corporal Locklear inadvertently commits suicide while distorting the Forerunner Crystal, recovered by Dr Halsey from underneath the ruins of CASTLE base. Halsey gave it to the Corporal, shortly before her departure, intending he is to destroy it rather than let it fall into the hands on the Covenant.

John faced a dilemma regarding the combat data on the Flood which Dr. Halsey had given him. Providing the standard data set to Lieutenant Haverson would protect Sergeant Johnson from possible experimentation by ONI. However, providing him the complete data, which contained reference to Sergeant Johnson's escape from the Flood due to his Boren's Syndrome, would result in Johnson's death.

John and the few remaining SPARTAN-IIs: Linda-058, Grace-093, William-043, and Fred-104, focused on finding a way to stop the Covenant from reaching Earth, the location of which had been discovered. They decided to destroy the Unyielding Hierophant. The SPARTAN-IIs infiltrated the station; after spending eleven hours on board, they arrived at a temple, where a copy of Cortana warned them of the Jiralhanae guards stationed at the temple. Linda took a sniping position and the other four Spartans entered the temple. They were ambushed by Brutes, and John was nearly killed, but the team managed to kill their attackers. Grace, however, was killed by three Brute Shot rounds. John activated the fail-safe on her armor, denying her compromise by the Covenant.

The team sabotaged the generators in the Unyielding Hierophant; as they escaped through a side door, the fail-safe on Grace's armor activated, disintegrating a Covenant lance. John, Fred, and Will were quickly spotted by three Banshees, but their Sangheili pilots were killed by Linda's sniper fire. The Banshees were then captured by the Spartans. John doubled back to retrieve Linda, who killed four more Banshee pilots who were attempting to kill John. They then escaped by destroying a glass atrium, and arrived back at the.

Vice Admiral Whitcomb and Lieutenant Haverson piloted the Ascendant Justice straight toward the Unyielding Hierophant. Whitcomb discussed the battles of the Alamo and Thermopylae with John, then prepared to fight the Covenant off while the Unyielding Hierophant's fusion reactor detonated. Each of the 500 Covenant ships maneuvered next to the Ascendant Justice. The Admiral and the Lieutenant were killed when the fusion reactor exploded, annihilating 486 ships of the Covenant fleet, leaving only around a dozen intact; these ships later joined the Prophet of Truth's rebuilt fleet in the attack on Earth. John left after witnessing Whitcomb's and Haverson's sacrifice, and arrived at Earth with the last members of his team, Linda, Will, and Fred, as well as Johnson and Cortana.

Battle of Earth
"Sir, permission to leave the station?"

- John-117

"For what purpose, Master Chief?"

- Terrence Hood

"To give the Covenant back their bomb."

- John-117

Aboard Cairo Station, John received the MJOLNIR Mark VI Powered Assault Armor and attended an awards ceremony with the newly-promoted Lieutenant Commander Miranda Keyes and Sergeant Major Johnson. The ceremony was interrupted by the arrival of the Fleet of Sacred Consecration, initiating the Battle of Earth. John successfully repulsed Covenant boarders from the station. Upon discovering a Covenant Anti-Matter Charge on board Cairo Station, John fought his way through waves of Elites, Grunts, and Drones until he reached the bomb and allowed Cortana to access and deactivate it by transferring her back to his suit. Afterwards, she chose to rejoin him despite his offer for her to remain on the station. He used the charge against the Covenant by launching himself and the device, via decompression of one of the station's launch bays, towards an Assault Carrier. A timely strike by Longsword interceptors opened a breach in the warship's hull, allowing John to direct the bomb into the ship's fusion core. He then proceeded to use the blast from the bomb to launch himself back into the.

John was then deployed to New Mombasa, East African Protectorate aboard the, in an attempt to board Solemn Penance. Both of the strike teams' Pelican dropships were shot down by a Scarab. John and the surviving Marines on his team fought their way to the other Pelican's crash site. After rendezvousing with Gunnery Sergeant Marcus Stacker at Hotel Zanzibar in Old Mombasa, the Master Chief destroyed Covenant units along the shore of the city as he chased the Scarab. Upon arriving at the edge of Old Mombasa, John received a Scorpion Tank from Sergeant Major Johnson.

After fighting through numerous highway tunnels and suburbs, John reached the city center, where Marines under the command of Staff Sergeant Marcus Banks were pinned down by Covenant forces. With the assistance of the Marines and a large stockpile of weapons, John boarded the Scarab and was able to destroy it and the Covenant forces protecting it. John was then transported to In Amber Clad to intercept the Prophet of Regret's flagship. When the flagship started to enter Slipspace, Lieutenant Commander Keyes was granted permission to follow it. John and all on board In Amber Clad were brought to Installation 05.

Installation 05
Forced to act quickly once at Installation 05, John deployed groundside in an SOEIV along with several Orbital Drop Shock Troopers. This team was tasked with locating and assassinating the Prophet of Regret. Cortana informed John of Regret's intent to fire Halo as soon as possible. He tracked the Prophet of Regret to a temple in the middle of a lake, but not before witnessing hundreds of Covenant vessels coming out of Slipspace, followed by High Charity. He quickly dispatched the Prophet of Regret, and escaped the temple shortly before it was destroyed by an overhead cruiser. John jumped off the edge of the structure and into the lake below.

Losing consciousness and being unable to swim in the lake, he was captured by the Flood's central intelligence, the Gravemind. Shortly after, the Arbiter was also captured. The Gravemind appealed to the common interest of the Flood and the humans share, that of not wishing the Halos to be fired. John agreed. The Gravemind then tasked both captives with locating the Index, sending them to the two most likely locations. John was sent to High Charity, interrupting a sermon by the Prophet of Truth. The conflict between the Sangheili and Jiralhanae was beginning, leading the Covenant on the path to civil war: John was caught right in the middle.

John chased the surviving Hierarchs through High Charity, eventually catching up to the Prophets and their Brute escorts. However, only a dying Prophet of Mercy, who had been compromised by a Flood Infection Form, was left to tell him that Truth was heading to Earth. John faced another crucial dilemma: the Covenant had the Index and could activate Halo; however, Earth's stood little chance of withstanding Truth's reassembled fleet. Ultimately, John followed the latter priority, forced to leave Cortana behind so that if Halo were activated, she would detonate In Amber Clad's reactors, not wanting to risk detonating them remotely. John boarded the Forerunner Dreadnought, which was bound for Earth, but not before promising to return for Cortana after he stopped Truth.

Return to Earth
"Master Chief, you mind telling me what you're doing on that ship?"

- Lord Hood

"Sir, finishing this fight."

- John-117

After a series of firefights, captures and escapes, John exited the Dreadnought and crash-landed on Earth, within an East African jungle, where he was found by Sergeant Johnson, the Arbiter, and the rest of their squad. Johnson believed the Chief to be dead, and requested heavy lifting gear in order to recover the Spartan's body. However, John awoke to battle-ready condition only moments later, showing his incredible tolerance to pain and shock. He attempted to attack the Arbiter, believing that the Elites were still the enemy. Johnson informed him that the two races were now allies, as the disillusioned Arbiter and the Sangheili had defected from the Covenant.

John and the Marines traveled through the jungle, searching for evacuation to a nearby military base. Johnson and his team split up from John and the Arbiter; the sergeant and his squad were soon captured by loyalist Covenant Brutes, although they were rescued by John and Arbiter. After taking heavy fire from Phantoms, a Pelican dropship evacuated the team to a UNSC base known as Crow's Nest.

The base soon came under attack, but not before Fleet Admiral Terrence Hood told John his plan. Lieutenant Commander Keyes decided to evacuate all forces, many of whom were injured. John, Thel and the remaining UNSC Marines defended the base during its evacuation, planting a massive bomb to destroy the base along with the invading Covenant forces. The Master Chief fought his way through many Brutes, escaping the explosion in an elevator. He met up with several Marine survivors underground, and they escaped the base and headed for the city of Voi along Tsavo Highway, crushing Covenant resistance on their way.

At the Battle of Voi, John pushed through many Loyalist forces as he made his way to what was believed to be the Ark. Rather, this turned out to be a device that opened up a portal to the Ark. With Marine support, John destroyed three Anti-Air Wraiths, a Scarab, and a Covenant Anti-Aircraft Battery, allowing Lord Hood's remaining frigates to fire upon Truth's Dreadnought, with little effect. Truth then activated and fled through the Portal with his remaining Loyalist forces, while the UNSC remained behind to determine their next move.

Just as the battle seemed finished, a Flood-infested Covenant warship crash-landed in Voi. John, Arbiter, and the remaining Marines fought to contain the Flood infection, learning that the only way to contain the Flood was to destroy the warship. During the battle, Shipmaster Rtas 'Vadum came to aid the UNSC. He deployed a Special Operations Sangheili strike team through Orbital Insertion Pods, assisting John as he was sent to retrieve Cortana from the cruiser, as it was believed that she was on board. Aided by 343 Guilty Spark, John retrieved a damaged data device and was brought aboard 'Vadum's flagship, Shadow of Intent. This data turned out to be only a message, rather than Cortana herself. The Sangheili were able to stop the Flood infestation by glassing the city and its surroundings, much to Hood's displeasure.

The Sangheili and the UNSC watched Cortana's recording, which contained a warning that High Charity, now overwhelmed and controlled by the Gravemind, was heading for Earth. However, she offered hope, with information of a way to stop the Halos from firing and neutralize the Flood threat. Convinced of the reliability of Cortana's message, John resolved to journey to the Ark, while Hood mobilized remaining UNSC forces on Earth. John accompanied a joint UNSC-Sangheili task force through the portal aboard the to the Ark.

Installation 00
"Thought I'd try shooting my way out—mix things up a little."

- John to Cortana

The Sangheili carried UNSC forces through the Slipspace portal which led to the Ark. The team was determined to stop Truth from activating the remaining six Halos. They descended in Pelicans while the Shipmaster's fleet fought hard against the Brute ships. They flew to the surface of the Ark to eliminate the Covenant in the area, to secure a landing zone for Forward Unto Dawn, and to find the Ark's Cartographer. Traveling in Scorpions, Warthogs, and captured Prowlers, John and other Marines located the Cartographer and learned that Truth was in the Installation's Citadel. John then escaped from the Cartographer and proceeded to assault the fortress.

John-117, The Arbiter, and a squad of UNSC Marines were assigned to separately attack three Barrier Towers, which were emitting a protective shield around the Citadel. Although John and Arbiter managed to deactivate two towers, Sergeant Johnson was captured in the battle, being spared to serve as a Reclaimer. John, Arbiter, and the Elites deactivated the last tower, lowering the shield. Just as the Shadow of Intent was about to destroy the Citadel, the Flood-controlled High Charity exited Slipspace, bringing the Flood into the battle and disabling the Shadow of Intent.

After defeating the last remnants of the Loyalist forces around the Citadel, including two Scarabs, John and the Arbiter entered the Citadel. Although Miranda Keyes had forced her way in, breaking through the central window with her Pelican, she was soon surrounded. As she hesitated before killing Johnson and herself, Truth shot and killed Keyes with a Spiker. Truth then forced Johnson to begin the activation sequence. In an unexpected turn of events, John and the Arbiter made a temporary alliance with the Flood to stop the activation of the Halos. The final Loyalist defenses were crushed by the Flood as John and the Arbiter reached Truth, who was already being infected by the Flood. Then the Arbiter executed him with his energy sword, while John deactivated the rings.

The Gravemind then betrayed John and the Arbiter, laughing as it had succeeded in preventing its own destruction. After fighting past waves of Flood, the two escaped. As they were leaving the Citadel, John saw a vision of Cortana that led him and the Arbiter to the exit. There, he learned her plan: a replacement for Installation 04 had been built by the Ark, and was not yet connected with the rest of the Array. Since the Halo was so far from the inhabited galaxy, John decided to activate the ring and destroy the Gravemind, but first headed to the remains of High Charity.

"You know me. When I make a promise..."

- John-117

"You...keep it. I do know how to pick 'em."

- Cortana

On High Charity, John battled his way through hordes of Flood, being taunted with images of Cortana falling into rampancy and by threats from the Gravemind. He finally reached Cortana, who still had the Activation Index from the first Installation 04. John then destroyed the city by overloading its backup generators. On his way out, Cortana detected a friendly contact, which turned out to be The Arbiter. High Charity exploded as the trio narrowly escaped on a Pelican.

Firing replacement Installation 04B
The final task for John, Arbiter, and Cortana was to destroy the Flood by activating the Installation 04b. The three landed on the Halo, finding that the Gravemind was trying to rebuild itself on the Installation. Flood dispersal pods released Combat Forms against John and the Arbiter, forcing them to fight their way up to the Control Room, where the ring could be activated. During the battle, Sergeant Johnson arrived to assist the Chief in battle.

After defeating all Flood forces around the Control Room, 343 Guilty Spark unlocked the door to the Control Room. Once inside, however, Guilty Spark realized that the team intended to fire the Halo before it could be completed, which would destroy the ring. After mortally wounding Sergeant Johnson, he then turned on John.

"You are the child of my makers. Inheritor of all they left behind. You are Forerunner. But this ring...is mine."

- 343 Guilty Spark, betraying the Master Chief

John stood his ground, even after being hit by several energy blasts, and fought against Guilty Spark. Although the Monitor seemed to be invulnerable, Johnson shot the Monitor, temporarily distracting him. He then handed John his Spartan Laser, and John destroyed Guilty Spark. Johnson's injury was fatal, and he requested that John "send [him] out with a bang," after handing over Cortana's data chip and imploring him, "Don't ever let her go."

Cortana then activated the second Installation 04, and the Arbiter and John fled to theForward Unto Dawn on board a Warthog, fighting the Flood and local Sentinels on the way. The team boarded the Dawn and escaped the firing and destruction of the replacement Installation 04. However, the Slipspace portal which was opened for them could not sustain itself under the stress, and its closure severed the ship in half, sending the Arbiter to Earth. John and Cortana were left drifting in space towards Requiem.

Missing in action
"I remember how this war started. What your kind did to mine. I can't forgive you. But you have my thanks. For standing by him to the end....hard to believe he's dead."

- Lord Hood to The Arbiter at the UNSC Hillside Memorial

"Were it so easy..."

- The Arbiter to Lord Hood

John and Cortana were presumed dead when they did not make it back to Earth. The forward half of the Forward Unto Dawn, bearing the Arbiter, crash-landed on Earth. Lord Hood commissioned a memorial near Mount Kilimanjaro in Africa in honor of UNSC servicemen lost during the war. As there were no pictures to remember him by, John's SPARTAN ID number, 117, was carved onto the memorial by an unknown party, and the UNSC Master Chief Petty Officer of the Navy insignia patch was taped beside his ID number. Ironically, he and a few other Spartans are the only ones truly Missing In Action.

Stranded in Space
"Wake me...when you need me."

- John's last words to Cortana

John and Cortana managed to survive the explosion of Installation 04B in the remaining cargo portion of the Forward Unto Dawn, but it was nearly powerless and, without airlocks or a bridge, could not be properly navigated. Cortana, relieved that John had survived, explained this to the Chief, and that it could take years before anyone could discover their distress signal. In a similar conversation to one at the end of Halo 1, Cortana listed what John did and told him "it's finished," and this time, John agreed with her. John placed himself in a cryotube, at which point Cortana said, "I'll miss you." John replied with "Wake me...when you need me."

In 2553, while still stranded in space, Cortana attempted to talk to John while he was still asleep. Unable to get a response from him, she recounted the history of the galaxy, seemingly unaware that John could not hear her, and showing major signs that she was descending into rampancy.



Requiem
Four years later in 2557, the Forward Unto Dawn arrives at the Forerunner Shield world named Requiem. Cortana wakes Master Chief from cryosleep when they are scanned by Requiem. Shortly after, the Dawn is boarded by Storm Covenant forces seeking to deny them access to the shield world. After shooting down a Covenant cruiser, Requiem opens and draws both the Dawn and the Covenant fleet into the shield world. John miraculously survives the impact and lands on Requiem, where Cortana reveals that she is descending into rampancy. John's undying loyalty to Cortana leads him to promising Cortana he'll get her back to Earth and getting Dr. Halsey to fix her, however Cortana states she cannot recover from rampancy. John presses on and navigates the wreckage, and while doing so, finds the  transmission of the, although faint.

Cortana tells John they need to hijack a Covenant ship and as they close in on the Forerunner Facility, the Infinity's signal clears up enough to hear a word. In the Forerunner facility, John and Cortana find a Localized Cartographer, revealing to John and Cortana that they are on Requiem. When John asks Cortana to find out what the Covenant Remnant are searching for, the Console is locked up by an unknown source. They reactivate the Cartographer and after doing so, the Transmission from the Infinity is picked up again although now it is much more clearer than before. Cortana attempts to contact the Infinity however to no avail, then suggests to John to use the Cartographer to find the Infinity's Location. The Cartographer refuses initially, however then points John to the Core of Requiem, which he doubts. Cortana states that the planet is hollow and that somebody could have gotten deeper than them. She then suggests to take a portal to the core from a Terminus on the far side of the Complex. John fights his way to the Terminus, which is situated atop a Tower.

Upon reaching it, Cortana attempts to open a Portal to the point of the Infinity's transmission location. When she tries to do so, The system responds with the Forerunner symbol for Reclaimer. She tries again, however when the portal opens, a large number of Promethean Knights spawn around them, however does not immediately engage. John then jumps into the portal, evading combat. They exit the portal somewhere near the core, close to a console. The "satellite" in the Center of the Core is amplifying the Infinity's transmission, however two beams coming from it are interfering with the "satellite". Cortana then opens a portal to an area near the first pylon, where john encounters the Prometheans. He fights through them and takes down the Pylon, which clears up the signal even more. Upon returning to the console, Several Storm Covenant ships exit slipspace at the core, and start heading toward the second pylon. John then portals near the second pylon, fighting his way to it and disabling it, making the transmission clean. John is then contacted by the Infinity's captain, who picked up John's IFF Tag. however when Cortana tries to warn the Infinity not to enter Requiem, but the signal received by Captain Del Rio is faint, thus the ship is ordered to move faster.

Cortana then tells the Chief to head to the satellite quickly, and upon doing so reveals the Covenant and the Prometheans in a firefight. John fights through them once more and upon reaching the "satellite", Cortana tells john to touch the 2 pillars with the Reclaimer symbols on them. The Chief does so and attempts to contact the Infinity, trying to warn the captain. Instead of being a satellite, it is actually The Didact's Cryptum, and the Didact needed a Reclaimer to be let out from it. The Didact is then released from the Cryptum. Stating that Humans were not fit to uphold the Mantle, he calls The Librarian, 'meddlesome' in attempting to protect humans and by simply waving his hand, regaining control of all the Prometheans; turning their Hardlights orange instead of blue, and the Storm Covenant, as he dismisses John and Cortana. he then jumps into slipspace and escapes the Core, destabilizing it in the process. John awakens and escapes the planet's core on a Ghost, and uses it to jump back to the surface just in time to watch the Infinity crash, with the Didact following it.

Rescuing the UNSC Infinity
Following the Didact, John fights his way through countless Prometheans in a jungle on Requiem, eventually encountering Commander Lasky and Commander Palmer as well as several Spartan-IVs and marines. Fighting alongside the marines through more Prometheans, John eventually discovers several Knights commanding Covenant forces. After extracting via Pelican, John joins forces with his successors as they fight their way to the Infinity in a scorpion, where Captain Del Rio orders him to take a Mantismech and deal with the Didact's cryptum outside the ship. Fighting his way through dozens of Prometheans and Covenant soldiers, John makes it to the outer hull of the ship where, after fighting off several waves of Banshees and Phantoms, he activates one of the Infinity's MACs where it and the rest of the ship's defenses repel the cryptum. After meeting up with Del Rio, John and Cortana tried to convince the captain of how much a threat the Didact really is, only for their efforts to be in vain as Del Rio was more concerned with having the Infinity escape and send a report back to FLEETCOM. When John attempted to make it a point about the Didact's vulnerability, Del Rio retorted with a veiled insult about John being the final Spartan-II before the bridge.

Destroying the Gravity Well and Escaping Requiem
John was later deployed along with Gypsy Company to destroy the Gravity Well keeping Infinity inside the planet. Hitching a ride with a Mammoth, he works his way down a canyon-like landscape, using a Target Locator to destroy a Particle Cannon en route. He later enters a Forerunner structure in hopes of disabling a certain restraining piece of technology, but is instead lured into what appears to be a shaft of blue light after Cortana goes missing. He is encountered by a memory of the Librarian in Requiem's system and told of the Didact's plans to use what is called the Composer on humanity after a remedial education on the history of the Human-Forerunner relations and the Forerunner-Flood War. In order to combat the Didact effectively, the Librarian speeds up his evolutionary process to render him immune to the Composing process, and he's released to fend off the Didact.

John destroyed the Gravity Well and returned to the Infinity, where he tried to convince Captain Del Rio of the threat the Didact poses. Del Rio refuses to believe it, and orders John arrested when he refused to give up Cortana after her rampancy worsened inside the Infinity's systems. However, Lasky decided to circumvent orders and instead gave John a Pelican to help in his efforts. John left the Infinity and went to disable two towers that were generating a shield around the Didact, and later attempted to use a control tower to trap the Didact inside Requiem. When that failed due to Cortana's worsening condition, John decided to hitch a ride on one of his escort Liches. When he got on one (not aboard, on), the Didact's Cryptum fused with a Forerunner ship in the planet, and he, along with the thousands of escort Liches and John-117, went through a Slipspace rupture, to the Composer.

Ivanoff Station and the Composer
After traveling through the slipspace rupture by hiding behind a piece of a Covenent Lich John-117 arrived with the Didact-Storm Covenenant forces at Installation 03. There the UNSC research facility falls under attack from the forces from Requiem. John-117 manages to enter the Lich and takes over the bridge, sending a broadcast to the station and warning them of the inpending attack and telling them to evacuate, halfway through the message Cortana's Rampancy stops John-117's broadcast, she also ignores his command to stop the Lich which is on a crash course with the station, while she continues to ramble through her rampancy, causing the captured Lich to crash into the station.

After awaking in the remains of the crash John-117 regains communications with the stations head scientist: Dr. Tillson he tells her to evacuate the station. She replies telling him the covenant have taken over all of the landing bays, John-117 then tells her to prepare for evacuation while he clears out a landing bay. He fights his way through the station defeating multiple squads of Storm Covenant before eventually clearing an evac station. From there he makes his way to Dr. Tillson and explains the situation of the Didact wanting to take the Composer from the station. John-117 asks for Dr. Tillson to give Cortana acess to the station's supply catalogue. While Cortana searches John-117 tells Dr. Tillson they need to move the composer, she claims this is impossible as it took three months and the largest ship the UNSC possesed to move the Composer from Installation 03, and claimed that unless John-117 is a lot stronger than he looked, the composer wasn't going anywhere.

John-117 then decides that instead of moving the composer they couldn't allow the Didact to take it. So he asks Cortana if there is anything that they could use to destroy the Composer, Cortana states there is a nuclear warhead that is available to be used. Dr. Tillson agrees with John-117, reluctantly, and states she will prepare the warhead while John-117 holds off the Storm Covenant forces. John-117 then makes his way to the outer parts of the station where Marines and Mantises are preparing for an engagement with Storm Covenant forces. John-117 and the Marines fight their way through the incoming waves and John-117 activates the Defense Grid. The entire time Cortana's Rampancy seems to worsen, as she laughs maniacally as she activates the Defense Grid. On his way back into the station Covenant forces are deployed onto the station near the composer. John-117 comandeers a Mantis and defends the artifact while Dr. Tillson continues to prepare the Warhead. After fighting through large waves of Covenant forces contact with Dr. Tillson was lost so John-117 to find her and the warhead. Upon entering the station John-117 enters an elavator to one of the cargo bays where Cortana states that the warhead is likely being kept. While on their way to the cargo bay Cortana warns John-117 that a large Kashimiere wave has been detected and a piece of debris crashes into the elavator damaging it and keeping it in place. The Didact then begins the process of removing the Composer from the Station. John-117 tells Cortana to find Tillson, but Cortana delves into another state of rampancy and ignores him. He tells her to ignore the Didact and the Composer, and find him Tillson.

Cortana researches Tillson's career files, stating her full name Cassandra L. Tillson, and that she was a student at Pegasi institute where she obtained a doctorate in Archealogy. Cortana then finds her on another deck in the station and claims her biosignature is stable. The elavator continues on its course and John-117 exits the elavator to find Tillson and and a large crowd of distressed scientists. Telling her that the Didact stole the composer, he inserts Cortana into the system and asks to check the flight catalogue for anything that can carry a payload. Tillson in confusion asks John-117 how the Didact moved the composer, then immediately asks what the Didact as the Didact charges a beam. John-117 asks Cortana to activate the Stations Defenses, but Cortana replies that they aren't reponding. Cortana continues to search through the catalogue but finds nothing, just before the beam fires Cortana says "Chief..." and looks at John-117, John-117 says "Cortana?" And the beam fires, digitizing all the members of the station and locks John-117's armor.

Infiltrating the Didact's Ship and Losing a Friend
An unspecified amount of time passes before John-117 awakens and finds Cortana sitting on the console. Cortana asks if he's ok. She then states she monitored the data pulse and that she could hear them, what was left of them. John-117 states they need to move. Cortana states sadly they're gone, John adds that more will follow if the Didact reaches Earth. Cortana returns to dwell on her ensuing rampancy and how they'll pair John-117 with another A.I. another Cortana model if Halsey let's them. John-117 states that he won't let that happen, Cortana ignores this and tells him the new A.I. won't be her. Cortana then begins to power up a broadsword in the hangar, claiming that whatever the Librarian did to John-117 worked. He then tells her that this wasn't over, not yet. Cortana agrees with him "not yet...".

John-117 makes his way to the hanger and enters the pilot seat of the Broadsword where it is released from the station and armed with the warhead. John-117 then blasts off in pursuit of the Didact. He finds the Didact's ship and approaches. Cortana states the plan of boarding the ship and finding the bridge when the Didact activates another slipspace jump. Cortana warns him that the Broadswords' shields aren't rated for Slipspace, but John-117 replies that the Didact's are before boosting forward to hide inside the Didact's shields. John-117 then begins to fly through the outer-hull of the Didact's ship, toward the composer, dodging pieces of the ship as they move and activate. Defenses attempt to destroy John-117. The Didact broadcasts a signal, stating his slight surprise at how John-117 wasn't composed, Cortana explains that the Didact was with the Composer and that they could destroy both of them at once. John-117 continues to fly through the outer hull of the ship until Cortana tells him that they're coming out slipspace, communication chatter from Earth warns them of the Fleet's knowing of the unknown ship. John-117   then attempts to contact Captain Del Rio on UNSC Infinity. John-117 asks where the captain is, Lasky states FLEETCOM wasn't happy with Del Rio abandoning John-117 on Requiem and that Lasky will have to do. John explains the Didact's intentions and they he and Cortana are in a Broadsword carrying a HAVOC grade payload and are intending to destroy the Composer. Lasky has the Orbital fleet engage the Didact and the Composer.

John-117 manages to fight through the remainder of the outer-hull and finds the composer and the Didact. He attempts to gain access to the composer but is cut off as the Didact seals it. John-117 informs Lasky of this and Lasky responds, telling John-117 that they could get him an opening if he could deactivate the shields. John-117 proceeds to destroy the shield and weapon generators and allows the UNSC Infinity to fire a MAC round into the Didact's ship giving John-117 an entryway. John-117 enters the ship and in an attempt to stop him the Didact causes the ship to close down on John-117. He survives the destruction of his broadsword and procures the nuclear warhead. From there he fights his way through waves of Prometheans and eventually accesses a terminal to try and deactivate the shield the Didact deployed to protect the composer. Cortana thinks of a plan and makes clones of herself composed of her rampancy. After fighting his way to the two generators and repeating this process John-117 goes to engage the Didact, before this the Didact claims John has failed and fires the Composer onto Earth. John goes to retrieve Cortana but the Didact destroys the terminal blast John away and destroying Cortana.

John proceeds through waves of Prometheans and finds a gravity lift that takes him to a light bridge where he can move toward the composer. The Didact challenges John by claiming he's persisted too long and gives him the opportunity to claim his "resolution" John turns on him and attempts to attack before being thrown back by the Didact dropping the warhead. Regaining his feet John-117 looks between his options of taking out the Didact or grabbing the warhead. He runs for the Warhead but is stopped by the Didact who lifts him and carries him over the slipspace rupture that is powering the composer. Claiming John is misguided and that humanity's imprisonment in the composer is a kindness. Before he can drop John into the abyss the Didact is surrounded by clones of Cortana who emerge from the lightbridge. Cortana claims that the Didact wouldn't mind her returning the favor, the Didact claims her passion for humanity is misplaced, but Cortana replies saying she isn't doing this for Humanity before attacking the Didact and binding him to the bridge freeing John who barely is able to grab the lightbridge. Pulling himself up, John charges the Didact and shoves a Pulse grenade into his armor. The Didact frees one of his hands and shoves John away and down onto the bridge. He frees his other arm and begins to slowly lift John into the air, but the grenade detonates and causes the Didact to lose focus and drop John and stumble off the bridge into the slipspace rupture below. John then proceeds to prime the warhead before taking one final look at Earth, then detonating it.

John wakes up and calls Cortana's name, asking if she reads. Receiving no reply, he begins to look around when a blue light draws his attention. A now human-sized Cortana steps out of a coding circle around them and approaches him. John asks how, and Cortana sarcastically replies that she's the strangest thing he's seen all day. John asks if they're where they are Cortana interrupts him saying it worked, he did it, just like he always did. John then asks how do they leave, Cortana says she isn't coming with him. Chief stubbornly refuses to believe this and claims they go together, and it was his job to protect her. Cortana corrects him saying it is their job to protect each other and that they did. John says he won't leave her and she sadly says his name before touching his armor for the first time and last time. She sighs and states she has been waiting a long time to touch John. After briefly touching John, she then begins to walk away but John tells her to wait. She says "Welcome home, John" before disappearing into the data-circle and leaving an emotionally distraught John. He is seen drifting in space where Pelican Nine-Sixer finds him. He is taken to the Infinity where he is greeted by a large force of marines and Spartan-IVs. He is later seen standing alone on the observation deck, looking out at Earth. Lasky appears and asks John if he can join him. John allows him and Lasky states he finds it odd when John calls him "sir". Lasky comments about how Earth is beautiful and he does not get to often seen it. Lasky reveals that he was raised on New Harmony and was trained in the Corbulo Military Academy, not seeing Earth until he was an adult, yet he proudly calls Earth home. Asking John if he talks a lot, he sympathizes with him and could tell he is grieving Cortana. Lasky says he lost people he cared about but not like the ones John went through. John replies that, as soldiers, their duty is to protect humanity, no matter the cost. Lasky states that John is saying humanity and soldiers are two different things, stating they're not machines, they're just people before leaving the deck to John. John then thinks back on Cortana's comment on Requiem, saying "She said that to me once. About being a machine." John is next seen entering a UNSC spartan IV training facility surprising most of the trainees there. He proceeds to an armor removal station where a team of scientists remove his armor and finally his helmet, where his face is seen. (his face appears if the campaign is completed on legendary)

Personality
"I guess some of your luck has rubbed off on me"

- Dr. Halsey

"We make our own luck, but I'll always be there when you need me."

- John-117

The personality of John is explored much more deeply in the books than the games. This is in order that players can more easily project their own personalities onto the Master Chief.

As a child, John strove to win at any situation, at all costs. This seems to have been a part of his character even prior to his conscription to the Spartan program, as he pushed himself to win at any game he played, including chess, gravball or King of the Hill. As his career progressed, he transformed his desire to win personal glory to that of victory for his squad, and by extension the soldiers and citizens of the UNSC. John is tenacious to complete any mission at hand, and often disregards his personal safety in order to win. Indeed, he has often emerged victorious from situations many would consider impossible. Still, even a Spartan is not devoid of fear, but John simply acknowledges it and puts it aside, while never openly showing it. John is generally stoic and taciturn, but not devoid of a sense of humor. He often makes dry remarks about the situation at hand; however, this seems to be more frequent when interacting with Cortana than anyone else, such as the other Spartans.

John is also known as a man of his word and will strive to keep any promise he makes, even at great personal risk. As he was forced to leave Cortana behind on High Charity, John promised to come back for her after dealing with the Prophet of Truth. Cortana chided him not to make a promise when he knew he couldn't keep it. However, despite incredible odds, John did keep his promise, as he fought his way through the Flood into High Charity to retrieve her. Upon finding her, Cortana was in a weak and damaged state. Nearing rampancy, the Master Chief told her, "You know me. When I make a promise..." to which Cortana replied "You keep it." This encouragement gave her the strength to compose herself after enduring the mental tortures of the Gravemind. John holds great personal respect for his trainer and mentor Chief Petty Officer Mendez, as well as Dr. Halsey, who he considers a mother-like figure. He appears to deny Halsey's claims about his extraordinary luck at several points in the Halo Legends episode "The Package".

In a strange twist of fate, one of John's closests friendships was with the construct Cortana, an artificial intelligence "born" from the mind of Dr. Halsey herself. Cortana was initially assigned to him for his mission to capture the Covenant Prophets. Despite some initial hesitation towards working with an AI out of fear of conflicting directives, John and Cortana quickly formed a formidable team and John realized quickly that Cortana would be a great help instead of a liability. The two's relationship evolved from a partnership to a close friendship over the course of Halo: Combat Evolved, due both the duration of the mission and the life-or-death situations they struggled through. During their adventures, John showed absolute trust in Cortana, believing in her even when Lord Hood was unsure of her reliability, being willing to trust her enough to risk Earth on her word that she had a way to stop the Flood. The two also had similar personalities: they both had a propensity to blow things up, with John commenting he wasn't sure which one of them was better at it. The pair also tended to enjoy executing high risk plans. After Cortana explained to John his strategy to use a disabled bomb to blow up a Covenant Carrier was crazy, he offered to leave her behind. Instead, she quipped, "Unfortunately for us both, I like crazy." When Cortana begins to go rampant, John becomes desperate to find a way to save her. Her absolute loyalty to him is shown when she restrains The Didact to save him, telling The Didact when he asks why she's helping humanity "I'm not doing this for mankind," showing she's helping out of loyalty to John. Cortana sacrifices herself to save John and he is clearly devastated by her "death," though he gets to say a goodbye to her in which she can finally touch him, something she has always wanted to do.

Although John has difficulty understanding the 'undisciplined' lifestyle of civilians, he is fiercely protective of their lives and humanity as a whole. The mass slaughter of civilians at the hands of the Covenant was enough to drive even the stoic John into a merciless rage. After the massacre of Draco III, John and his Spartans remained on-site until every Covenant soldier responsible for the atrocity was dead.

John is known to show an exceptional care for soldiers under his command, while at times viewing them as a liability rather than an asset. By 2552, after his experiences on Halo, John acknowledged to Corporal Locklear that, armor and enhancements aside, there was little difference between a 'normal' soldier and himself. This is not to say that John was previously without compassion. During the Battle of Installation 04, when searching for the survivors of the Pillar of Autumn, a Marine named Fitzgerald was wounded by a Grunt with a Needler. John-117 retrieved a first aid kit and expertly treated the wound, taking time to ask the Marine if he was alright. By 2552, most members of the UNSC held "the Master Chief" in complete awe, even amongst his Spartan comrades. His exploits and prowess quickly made him a legend in his own time, and his mere presence on a battlefield was enough to inspire the hope of victory regardless of the odds.

Age
John's age is affected by the same ambiguities as all beings who undergo extended voyages through space. By technical human Earth years, John is approximately 46 years old in 2557. However, during the 27 Earth years that he has spent fighting the Covenant, considerable time was spent in Slipspace. He also spent 4 years in cryo-chamber while stranded in space. The aging process is slowed in slipspace by deep sleep in cryo-chambers; in which cellular aging can be halted almost completely. Also, one could expect that individuals participating in slipspace travel might be subject to the timedilation associated with travel at relativistic speeds, so there could be more discrepancy involved there as well.

Appearance
Until the release of Halo 4, John-117's face has never been seen in the games, and therefore his appearance is left mostly to one's imagination. The novels Halo: The Fall of Reach and Halo: The Flood give some insight to John's appearance. Early in Halo: The Fall of Reach, when Dr. Catherine Halsey and Lieutenant Jacob Keyes go to Eridanus II to observe John as a child, he is described as "a typical six-year-old male, with tousled brown hair and a sly smile that revealed a gap between his front teeth". In Halo: The Flood, referring to John in 2552, he is described as having "Short hair, with serious eyes, a firm mouth, and a strong jaw." He is described as being unnaturally pale, a consequence of spending most of his time in his armor.

In the ending cutscene of Halo: Combat Evolved, John takes off his helmet, and the camera pans upward, leaving the head obscured by the ship window frame as he sets the helmet to his side. Some people have used Halo: Custom Edition development mode to move the camera. However, Bungie's 3D artists did not produce a separate character model for this occasion, just a separate helmet model; if the animation is viewed from inside the ship, it appears as if John takes off his helmet, revealing an identical helmet underneath. Players have also found an Easter Egg in the Halo 3 Beta. Using a Mongoose, players can reveal what looks like a face in a Spartan's helmet. However, Bungie has confirmed that this is Marcus R. Lehto's face, not John's.

For the first time, John's face was shown without a helmet in Halo: Helljumper Issue 1. The comic illustrated the fight between John and four ODSTs. As expected, his face is seen from the side and is covered up in shadow, hiding any specific facial features.

John's face can be seen clearly on the front cover of Halo: The Fall of Reach - Boot Camp Issue One as a six year old child.



In Bungie's Happy Halodays 2010 holiday card, the back of John-117's head can be seen since he is not wearing his helmet in which he has dark brown hair.

Franchise development director Frank O'Connor gave a description of Master Chief's appearance on October 9 in an interview with GameTrailers: “an older man, almost painfully pale, almost albino white, with pale blue eyes, reddish hair, close cropped to a skin head, and maybe the last remnants of freckles he had when he was a kid.” He also confirmed that Halo 4 would not actually depict Master Chief's appearance. This however is somewhat untrue, since in the Legendary ending of Halo 4, in a post-credit cutscene John is shown walking into a large hall which consists of Spartan IVs, and has his armor removed. As his helmet is removed, the camera pans into his eyes so a part of his face is shown, consisting of the description given by Frank O'Connor.

Trivia

 * Spartan-117's personality is explored more thoroughly in the books than in the games for gaming purposes, so that the gamer can incorporate their identity with the Master Chief. This is because the 'John-117' character, in Fall of Reach, was Eric Nylund's (and is widely accepted as Bungie's) own personal creative stand in for the Master Chief character.
 * John's birth year may be a pun on his ID number, 117 (2+5=7, combined with 11 and reversed is 117)
 * Through modding, it is possible to see a Master Chief hidden behind a pillar in the Halo 2 level "The Heretic".
 * John-117 is voiced by Steve Downes in the Halo trilogy, in Halo: Reach Firefight mode, and Halo 4.
 * Fans have many theories as to the significance of his number, 117. Inside the Halo Universe the number was randomly assigned, but Bungie's choice has been theorized upon in many ways. For more, see List of Biblical References in Halo. It was possibly chosen for its mathematical connections to 7, Bungie's favorite number, since $$1\times1\times7=7$$ and $$7^6=117649$$. John 1 Chapter 1, Verse 7, is a passage referring God who relinquished all evil from the world so people could believe, hence 'Believe' being part of the advertising campaign for Halo 3. Additionally, the song Remembrance is 1:17 in length, as well as Prepare to Drop. It is interesting to note that in the year 117, a man named "John I" became the 7th Bishop of Jerusalem. This covers both his name, John-117, and Bungie's apparent love for the number 7. It could also be probable that John-117 is named partially in honor of "John Spartan," protagonist of the movie Demolition Man, who was kept in cryogenic storage as "Prisoner 117" for forty years. It could just also be a play on James Bond's number, 007. Or even a reference to the 1998 alien invasion TV series First Wave, whose main character was referred to as "Subject 117". Or possibly because 77 seconds in minutes is 1:17 minutes. It is also worth noting that on the periodic table of elements, element 117 is an artificially created halogen (note the "halo" prefix" and being "man made"). As well, halogens have 7 valence electrons (another possible reference to Bungie's favourite number). On a final note, ex Guns N' Roses' member Izzy Stradlin's second solo studio album is called 117°.
 * In both Halo: Uprising and Halo 3, John is referred to as Sierra-117. This is a military-appropriate identifier using the Phonetic Alphabet.
 * Bungie's refusal to show John's face has been parodied many times in popular culture.
 * A wax sculpture of the Master Chief can be visited at Madame Tussaud's, L.A. and in Amsterdam. He was the first video game character to become a Madame Tussaud's wax sculpture.
 * Fable II makes a reference to the Master Chief with a character of legend named "Hal", also called the Minstrel Chief. The armor featured (clearly inspired by Halo's MJOLNIR Powered Assault Armor) is known as "Hal's Armor". The Energy Sword also makes an appearance as one of the first weapons you can attain with the Collector's Edition of Fable II. The Assault Rifle can be acquired on the Knothole Island DLC as "Hal's Rifle", and has the largest magazine of any ranged weapon in the entire game, although its damage is low to average. In addition, with the Special Edition, the player can obtain the title "Master Chief" for their hero for free from any title vendor.
 * At Comic-Con 2010, Frank O'Connor hinted that future media featuring the Master Chief after the events of Halo 3 may be produced.
 * In the Halo: Reach level "The Pillar of Autumn" it is possible to see a quick glance of John during the end cutscene. Holding the right thumbstick to the right during the hangar scene will reveal the Spartan in a cryo-chamber.
 * When previewing John's voice in Halo: Reach Firefight, he will reply with references to the Halo Trilogy.
 * "John" is one of the name options for customized Loadouts in Halo: Reach, along with the members of Noble Team and several SPARTAN-II's.
 * In Halo: Reach, on the Heroic difficulty with Campaign Scoring on, every time the player kills a Brute with an explosive weapon (such as a grenade, Fuel Rod Gun, Rocket Launcher, etc.), the score is 117.
 * In an episode of American Dad, when Steve is in the hospital after an accident, the person in the other room's bed name is John and the room number is 117, probably a reference to John-117.
 * One possible reference to 117 is the enlistment year of The Rookie, 2547. 4+7=11 and 2+5=7, making a 117.
 * The above reference could be done a second way; with 2+5+4=11 and therefore creating 117.
 * Reviewers, such as Kotaku, have pointed to John's silent and faceless nature as a weakness to the character, while other publications said this attribute allows players to better assume his role.
 * Gaming magazine Electronic Gaming Monthly named the Master Chief as the eighth greatest video game character ever.
 * John-117's rank is seven words long, another possible and likely reference to 7 by Bungie.
 * Coincidentally, the 2007 film 300 (which is a movie depicting the battle between the Persians and 300 Spartans) has a run time of 117 minutes.
 * Also in the movie "Demolition Man", Sylvester Stallone's character is named John Spartan.
 * John-117 is the only known Spartan with the rank of Master Chief Petty Officer.
 * John-117 (Named 'Master Chief') appeared in one Nice Peter's (A famous YouTuber) Epic Rap Battles of History, battle rapping against 300's King Leonidas. In this, he makes many references about his games, like, "They built a monument to my sins," and, "You're the soldier they need you to be". He mentions Cortana, and her intelligent abilities. He referred to a Covenant weapon, the Plasma Cannon. He even spoke of many gamer's way of celebrating a kill in multiplayer games, 'T-Bagging'. He was played and voiced by Peter Shukoff.
 * If a player would want to somewhat recreate John-117's concept art in Halo: Reach, they would need MJOLNIR Mk. VI or MJOLNIR Mk. V base helmet, MJOLNIR Mk. V or FJ/PARA left shoulder, MJOLNIR Mk. V or FJ/PARA right shoulder, UA/Base Security[W] (For the missing upper-frontal chestpiece) or DEFAULT chest piece, DEFAULT wrist, DEFAULT utility, DEFAULT or GOLD visor,Mk6=GRENADIER knee guards and Mk5=FJ/PARA or GUNGNIR knee guards, DEFAULT armor effect, and JOHN S-117 firefight voice. Color=Olive though Sage is also acceptable.
 * In Halo: Reach, you can purchase Master Chief's Firefight voice in the Armory for a price of 150,000 credits.
 * John 117's 'luck' and the prevalence of luck as a theme in his being chosen by Cortana is slightly reminiscent of the novel Ringworld by Larry Niven. This novel also contains an ancient ring-world built by a now-disappeared civilization, where one of the main characters (Teela Brown) is chosen to be part of the mission 'due to her luck', and to bring luck to the whole expedition. Luck as an inherent (psionic?) ability is explored further in that series of books.
 * In the game Duke Nukem Forever you can find his helmet and chest armor in a truck. Duke is asked to wear the armor then says "Power armor is for pussies." The person that asked him then asked if he would like a gun instead.
 * John-117 is the only character in the trilogy to witness the death of all three High Prophets.
 * John-117 was listed on Gameinformer's top ten list of Space marines, being listed as #2, under the Doom Guy of the Doom franchise.
 * A Master Chief Minecraft skin was released on the Xbox LIVE Marketplace, along with a Brute Major, Grunt Minor, and other characters.
 * The Halo 4 version of Master Chief's avatar armor was given out to those who played Halo 4 at E3 2012. It is now available on the Avatar Marketplace for 320 Microsoft Points.
 * The Halo 4 version of Master Chief's armor sports the "117" number in braille (written "⠁⠁⠛") on the left side of the chest plate.
 * According to the Halo 4 Scanned Trailer, John has brown hair and blue eyes.
 * In the mini-series: Halo 4: Forward Unto Dawn, John is physically portrayed by Daniel Cudmore, known for playing the role of Colossus in the X-Men movies, and is voiced by Alex Pucinelli.
 * In Halo 4, Master Chief speaks much more often than in the other games, probably due to bring out his character more than in previous Halo titles.
 * John's preferred weapon is the UNSC Assault Rifle(MA5 Series). He uses an Assault Rifle in all the books that he is featured in and all the games that he appears in except, Halo 2.
 * In all four Halo games, John-117 is seen falling or crashing early in the campaign; in Halo: Combat Evolved, he crashes to Installation 04 in a life boat; in Halo 2, he freefalls from Cairo Station to the Covenant assault carrier and then to In Amber Clad; in Halo 3, he falls to Earth from the Forerunner Ship; and in Halo 4, he crashes to Requiem with the wreckage of Forward Unto Dawn.
 * John-117 is the only known Spartan-II to set foot on a Halo Installation in canon.
 * It is possible to unlock John-117's Mark VI armour in Halo 4 multiplayer by completing the campaign on Legendary difficulty.
 * As of the events in Halo 4, John-117 is the sole surviving participant in the events of Halo.

List of Appearances

 * Halo: Combat Evolved
 * Halo 2
 * Halo 3
 * Halo: Reach (Cameo)
 * Halo: Combat Evolved Anniversary
 * Halo 4
 * Halo: The Fall of Reach
 * Halo: The Flood
 * Halo: First Strike
 * Halo: Ghosts of Onyx
 * Halo: Glasslands
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * Halo Graphic Novel
 * Halo: Uprising
 * Halo: Helljumpers
 * I love bees
 * Halo Legends
 * The Package
 * Halo 4: Forward Unto Dawn

Related Pages

 * Thel 'Vadam
 * MJOLNIR Powered Assault Armor
 * SPARTAN-II Program
 * Cortana
 * Avery Johnson
 * Franklin Mendez (Mentor)
 * Catherine Elizabeth Halsey