Master Chief (Mark V Armor)

John was an unknowing child who excelled at always being at the top. He never lost and this was one of the qualities that Dr. Halsey adhered for in the SPARTAN project. Even at a young age, he was exceptionally strong and fast compared to other children of his age group and fortunately, it made him stick out long enough for him to be noticed. When Dr. Halsey and Lieutenant Keyes first observed John in action on his home planet of Eridanus II in the small city of Elysium. He qualified beyond their expectations having extraordinary reflexes, physical proportions and and extremely aggressive drive for success. He was chosen out of 150 possible candidates and was given one last task by Dr. Halsey to determine whether was suitable or not. He was asked to watch an old coin and choose which side it would land on. As it flew through the air, John snatched it before it even landed and chose correctly, the Eagle. Even at the young age of 6, John was referred to by Dr. Halsey of having amazing eye-sight.

Alongside 74 other children, John was conscripted and covertly kidnapped from his parents to initiate his SPARTAN training. In their absence, flash clones of the children were left behind to avoid any suspicion or cause any concern. John and the other candidates were taken to the planet Reach where Dr. Halsey informed them of the SPARTAN- II program they were to be initiated into and how they would become humanity's greatest protectors. The following morning, John awoke in his quarters and looked upon his new name: John-117.

At the age of eight, the Spartans underwent their hardest training mission to date. They were dropped in the middle of the forest with no direction, no map and no supplies. They were only told to reach the Pelican extraction sight and that the last child to make it would have to be left behind. This angered John since the Spartans considered each other family and couldn't bear to live with that. As they located the dropship, the Spartans all looked to John as their leader, which surprised him but he had to accept it. John and the Spartans mistook the armed guards around the Pelican as hostiles due to the lack of uniforms, even though they were UNSC Marines. John devised a plan to dispatch the soldiers, re-take the Pelican dropship and get everyone home safely even if it meant disobeyed orders. Mendez and Halsey recognized this and promoted John to squad leader and solidified his role as the Spartan-II's overall leader, and nobody was left behind.

At the age of 14, John and the other Spartan II's underwent the extremely painful Augmentation process. Only 33 of the Spartans survived while 30 died and 12 were left physically disabled. This procedure granted the surviving Spartans with:

Enhanced eyesight- virtually able to see in complete darkness Enhanced speed- able to run at bursts of 55 KPH Enhanced strength- lift three times their body weight Enhanced musculature- near-unbreakable skeleton Enhanced reflexes- Twenty millisecond reaction time, even quicker in combat After this augmentation, John was stated to have the body of an 18 year old Olympic athlete.

By August of 2558, John had completed two hundred and nine military operations, including one hundred and thirty-six full campaigns; more than anyone other UNSC personnel on record at the time. Though John has commanded nearly every Spartan-II at one time or another, the lion's share of his career has been spent as fireteam leader of Blue Team. His actions during the Human-Covenant War earned him every major UNSC service medal and combat award, save for the Prisoner of War Medallion, as well as several dozen civilian honors.

Chief wears green Mark V MJOLNIR Powered Assault Armor. Its components are: Titanium Alloy Outer Shell Titanium Nanocomposite Bodysuit Hydrostatic Gel Reactive Metal Liquid Crystal Layer Magnetic Weapon Holder Strips Rechargeable Energy Shield covering armor Pressure Seal Biofoam Injector Port Fusion Reactor Force-Multiplying Circuits Reactive Circuits Power Supply Control Unit

Cortana is a "smart" AI formerly in service with the United Nations Space Command. Unique and exceptionally powerful even among smart AIs, she was one of the most important figures in the Human-Covenant War, and served as John-117's partner.

The MA5B assault rifle is a standard-issue automatic rifle utilized widely by the United Nations Space Command, particularly the UNSC Marine Corps.

The M6D, aka the Magnum, is a recoil-operated, magazine-fed handgun

The United Nations Space Command (UNSC) is the military, exploratory, and scientific agency of the Unified Earth Government (UEG) and has acted as the emergency governing body of the human race.

The Covenant is a massive religious hegemony of multiple alien species that completely controlled a large portion of the Orion Arm in the Milky Way Galaxy for thousands of years. The Type-25 plasma rifle, used by Convenant infantry, is a battery-powered directed-energy weapon that is capable of fully automatic fire. The Type-25 Directed Energy Pistol, the plasma pistol, is a Covenant infantry weapon

The Sangheili, or "Elites" as they are known by humans, served as the military leaders of the Covenant. The Sangheili are the only race within the Covenant permitted to build and command starships within the Covenant, though the crews are always composed of a mix of races. The Jiralhanae, or "Brutes" as they are known by humans, were the most recent addition to the Covenant, and served as soldiers and bodyguards within the Covenant military. The Lekgolo are a race of worm-like creatures that can combine to form large, intelligent assemblages called Mgalekgolo, known by humans as "Hunters". Clad in nearly impenetrable armor and armed with their trademark Assault Cannon, they served as the Covenant's heaviest ground troops. Hailing from Balaho, the Unggoy, or "Grunts" as they are known by humans, were the most common and low-ranking caste of the Covenant. They breathe methane gas, and thus must wear a large tank on their back full of methane to survive on other planets. The Kig-Yar, or "Jackals" or "Skirmishers" as they are known by humans, were the scouts and marksmen of the Covenant military due to their superior senses.

The Human-Covenant War was instigated by the High Prophets of the Covenant following a discovery which led them to believe that humans were directly related to the Forerunners, contradicting their ancient religion. Seeking to keep various political and religious orders intact, the High Prophets declared a holy war of genocide against the human species, and the discovery of their relation to the Forerunners was kept a secret. With superior firepower, numbers and technology, the Covenant would repeatedly overpower the UNSC across hundreds of human-inhabited worlds, including the heavily defended strongholds of Reach and Earth. Humanity would win only scattered and costly victories.