Since Time Immemorial

The story of Halo begins a million or so years before Master Chief ever picked up a Battle Rifle. The lengthy fictional history regarding the dawn of the universe helps inform all the zealotry and ancient resentments that came after.

In the beginning, there were the Precursors. These were basically gods, complete with the ability to create life. First came the Forerunners, a peaceful race adept at huge technological advancements. Then came humanity. Finally, the Precursors made the monstrous race called the Flood, in order to test both of their other creations. All of these plans would eventually backfire terribly.

The Forerunners rebelled against the Precursors. Humans began to populate the galaxy, with the help of Precursor tech, but in the process started a war with the Flood. Sometime during this period of unrest, the Forerunners made autonomous sentries named Prometheans. To make matters worse, in the process of driving back the Flood, humanity stepped into Forerunner space, and inadvertently began a war with them too. Led by a general known as the Didact, the Forerunner victory was so decisive that it drove humans back to the Stone Age.

With the Flood pushed back, the Precursors guarded against a return by creating Halos: giant weapons that can destroy all organic life. The Precursors also made Shield Worlds, special areas immune to the effect of the Halos so that they could protect a chosen few if the weapons ever had to be used. The Didact openly opposed this plan, and for it he was imprisoned on Earth along with his wife, The Librarian. She put her time to good use collecting samples of all the living species, and placing them in an Ark.

You can’t keep a good Flood down, as it turns out. They came back and began slaughtering Forerunners, who created an artificial intelligence called Mendicant Bias to fight the Flood. It also tested a Halo, awakening the last Precursor. But given that the Forerunners didn’t much like Precursors in the first place, Mendicant Bias captured him.

Meanwhile, the Didact was broken out of his earthly prison by a Forerunner. When The Didact died, he transferred his memories to this Forerunner, who became the Second Didact.

The last Precursor turned out to be a Flood leader in disguise, known as a Gravemind. He tricked Mendicant Bias into turning a Halo against the Forerunners. The Second Didact capitalized on this opportunity to seize control of the Forerunner military. As part of this effort, and because his efforts to create an immunity to the Flood failed, the Second Didact used a device called the Composer to turn organic creatures into the digital Promethean sentries. This made them immune to infection, but he quickly began forcibly using it on humans to turn them to his soldiers.

Mendicant Bias began open rebellion against the Forerunners, taking control of several Halos. The Forerunners destroyed them, and countered by taking control of one of the two remaining Halos.

One of the Didact’s associates, Chakas, was used as a template to build another artificial intelligence called Guilty Spark. The Forerunners also created another A.I. called Offensive Bias as a counter-measure against Mendicant Bias. There’s just no problem the Forerunners won’t try to solve with an A.I.

Meanwhile, The Librarian continued her work on Earth, secreting away the Ark and some recordings between herself and the Didact.

Finally, the war between the Forerunners and Flood reached an apex. The Forerunners turned to the nuclear option, having Offensive Bias trigger a Halo to wipe out almost all of the organic life in the galaxy. Whoops! Fortunately they had the Librarian’s collection of genetic data stored in the Ark. They repopulated the galaxy and left it to evolve according to its own devices.

Humanity began to develop again, but so did other races. While humans were still stuck in the Bronze Age, two of these evolved species, the Prophets and the Elites, began to fight against each other. They both used Forerunner technology, but the Elites were more focused on discovering ancient artifacts. Soon after, the two declared a truce and formed the Covenant.

The Human Threat

All was well for a few thousand years or so, but the peaceful truce was interrupted by the sudden presence of humans. After colonizing Mars in the late 21st century, humanity achieved an unprecedented period of technological advancement. It formed the United Nations Space Command (UNSC) for a more unified military, and then discovered faster-than-light travel.

Almost 300 years later, John-117 was born. The UNSC began its research into the Spartan II program, and selected John 117 as a candidate. He ultimately became the Master Chief. As he was undergoing the program, though, humanity had its first encounter with the Covenant. It was a violent one, naturally, which kicked off a full-scale war.

Let the Games Begin

In the course of the war, UNSC ships slipped through a gateway to a Forerunner Shield World, where it also encountered the Flood for the first time in a million years. The ship’s sergeant activated the slipspace drive, destroying the planet and that particular Flood threat. (Halo Wars)

The Covenant took an offensive posture in the war, attacking the planet Reach. Reach had grown into the largest human colony, and was the most populated center of humanity outside Earth. A Spartan group called Noble Team helped evacuate the cities. The team also discovered an artificial intelligence known as Cortana with Forerunner secrets, and secured her on a human ship, the Pillar of Autumn. (Halo Reach)

The Pillar of Autumn reached one of the last remaining active Halos, with Master Chief and Cortana on-board. Master Chief was woken from cryosleep and given Cortana for safekeeping just before the ship crashed. In the course of exploring the Halo, he inadvertently unleashed the Flood. Guilty Spark was also on-board the Halo, and attempted to trick Master Chief into activating the weapon, but Cortana stopped him. He ultimately detonated the Pillar of Autumn’s engines to destroy the Halo. (Halo)

The Covenant had been searching for the Ark, and found the trail led to Earth. Master Chief found himself on yet another Halo. The Covenant began to splinter at this point, leading various groups to fight against each other. Master Chief and humanity were no longer fighting against one cohesive army, but rather several different warring factions. The Arbiter and his Covenant Elites were unlikely allies, helping fight against Covenant Prophets and the Flood Gravemind. A failsafe on the Halo prevented any from firing unless activated from the Ark, so the race to reach it began. (Halo 2)

With seemingly the entire galaxy converging on Earth, even more temporary alliances formed. The Hive Gravemind formed a truce with the Arbiter and Master Chief, in an attempt to prevent the activation of the Halos. Naturally though, once its goal was complete, the Flood went back on its word. The Ark began auto-constructing a replacement Halo for the one that was destroyed. Master Chief detonated it, destroying the Ark along with it. The Arbiter and Master Chief escaped from the wreckage on the Forward Unto Dawn, but the ship was split in half by the force of the detonation. The Arbiter returned to earth, but Master Chief and Cortana were isolated and floating in unknown space. He had ended the Covenant War, but been lost in the process. (Halo 3)

Four years later, Master Chief was woken from cryosleep again by Cortana. The two had landed on Requiem, a Shield World, and had to fight hostile Covenant along with the Second Didact’s Prometheans. Making matters worse, Cortana was going through the early stages of “rampancy,” a state in which A.I.s like her eventually destroy themselves. Master Chief aimed to reach Earth, to find Cortana’s creator, Dr. Catherine Halsey. Then, in an attempt to protect a human ship from Requiem’s gravity well, Chief accidentally released the Didact. The Didact promptly took control of the Prometheans and Covenant on the planet.

Chief was contacted by The Librarian, who explained the history of the Didact and the Composer, and accelerated Chief’s evolution to make him immune to the Composer. Chief and Cortana raced to a Halo ring where the Composer sat just off-site. The Didact used it, converting everyone on-board but Master Chief. Chief subsequently defeated the Didact, and activated the nuclear bomb. Cortana sacrificed herself to save Chief from the blast, and he was retrieved by UNSC forces. (Halo 4)

Master Chief: Most Wanted

In the ongoing serialized pocast Hunt the Truth, we've received some table-setting for the upcoming Halo 5. The first season focused on Benjamin Giraud, a journalist on the payroll of the Office of Naval Intelligence (ONI). Tapped to write a fluff piece about the Master Chief, Giraud noticed inconsistencies in the official accounts, which drove him down a deep rabbit hole of conspiracy and deceit that exposed the dark roots of the Spartan program.

Against this backdrop, Master Chief himself became a wanted man. Caught on tape breaking into a peace negotiation and starting a firefight that left several people dead, ONI had determined that he went rogue. Giraud doubted the official account, and found evidence that the tapes had been selectively edited. Master Chief hadn't assassinated a peaceful leader at all--he had interrupted an assassination plot from insurrection forces within the leader's midst. 

Just as Giraud prepared to expose the official account as a fraud on a live show, however, the ONI account changed to redeem Master Chief as the hero, and Giraud's own evidence was doctored to appear as if he were part of the conspiracy. The first season ended with his career and safety crumbling around him as he was arrested.

The second season, still in progress, deals with one of Giraud's contacts: an ONI double-agent who spent years posing as the revolutionary leader Faro. It remains to be seen how the first season's revelations, and this second season, will tie into Locke's hunt for the Master Chief in Halo 5.