GameSpot may receive revenue from affiliate and advertising partnerships for sharing this content and from purchases through links.

The Halo Story So Far -- Catch Up Before Halo Infinite

The Halo Universe has one of the richest and densest mythos in all of gaming, and we broke down exactly what you need to know to understand its story.


At first glance, the Halo franchise seems like the standard "super-soldier kills aliens, saves the universe, and chews bubblegum" narrative that we've seen a billion times before. But despite the seemingly straightforward story told across its six mainline titles, the Halo Universe has one of the richest and densest mythos in all of gaming, delivered through numerous spin-off games, novels, movies, short films, graphic novels, and even an audio drama.

So with Halo Infinite promising to build on all this lore, it can easily feel overwhelming to newcomers. Don't worry, as we've got you like Cortana has the Master Chief, because we're going to take you on the Great Journey through the complete timeline of the Halo franchise.

Please use a html5 video capable browser to watch videos.
This video has an invalid file format.
Sorry, but you can't access this content!
Please enter your date of birth to view this video

By clicking 'enter', you agree to GameSpot's
Terms of Use and Privacy Policy

Now Playing: The Complete Halo Timeline


While the Halo games started with Halo: Combat Evolved, the story of the Halo universe begins much earlier in 15,000,000 BCE.

Some 15 million years ago, give or take a couple thousand, an ancient race known as the Precursors seeded the galaxy with life, creating species such as humans and the Forerunners. They hoped that one day, one of their races would carry the Mantle of Responsibility, their belief that the "most developed" species would become benevolent stewards of life in the galaxy, protecting biodiversity and not getting involved in conflicts between different species unless it was necessary. Kind oflike the Federation and the Prime Directive from Star Trek, though with a bit more smug superiority.

Eventually, 5 million years later, the Precursors choose humanity to carry the mantle, making the Forerunners jealous. The Forerunners rebelled against their creators, forcing the Precursors to flee the Milky Way and retreat to the Large Magellanic Cloud, a small dwarf galaxy orbiting our own. With little to survive on, most of the remaining Precursors turned themselves into dust for later rehydration.The Forerunners took up the Mantle, twisting the ideology to mean that they had a duty to keep "lesser" races underneath them.

Humanity and the Forerunners lived mostly on separate sides of the galaxy, until one day, 100,000 years ago, humanity began destroying Forerunner worlds. Angered, the Forerunners and humanity began a 1,000-year war, with the San'Shyuum (known later to players as the Prophets) allying themselves with humanity.

However, humanity wasn't destroying Forerunner planets as an act of aggression, but because they were being pushed out of their space by the Flood, a parasitic life form that consumed everything it touched and turned it into more Flood. The Forerunners, who had yet to encounter the parasite, believed the Flood to be a lie told to justify human aggression.

During the war, humanity found the last living Precursor called The Primordial, who revealed the horrifying origins of the Flood. After turning themselves into dust, the Precursors became corrupted. It mutated them into horrifying Flood creatures under the control of the singular Gravemind. The Gravemind decided to get revenge on all life in the galaxy by removing free will and turning everything into the Flood.

Humanity continued to wage war against both Forerunners and Flood, nearly beating both and forcing the Flood to retreat, but eventually losing to the Forerunners. As punishment, the Forerunners devolved humanity to hunter-gatherers and exiled them to some random planet called Earth. The San'Shyuum were quarantined to their homeworld, forbidden to ever leave. Yet, while the war was won, the Forerunner military was exhausted and a political schism began to brew in their government, cementing the tragedy to come.

With humanity gone, the Flood began infecting Forerunner worlds, making them realize the threat too late. Realizing they couldn't win against the Flood, two political factions formed. The Didact wished to create shield worlds--planets completely encased in metal to protect them from the Flood--while the Master Builder wished to create the Halo Arrays, giant rings that would destroy all life in the galaxy, thereby starving the Flood, with an arc being created to reseed the galaxy afterward.

The Halo Arrays were chosen, so the Didact rebelled using a technology called The Composer and created an AI army of Prometheans from Forerunner and human warriors alike. However, the Didact was defeated, imprisoned on a shield world called Requiem, and forced into a long nap in stasis. But we hadn't seen the last of him.

Focused on the Halo array, the Forerunners built an AI called Mendicant Bias to fight the Flood. However, the Flood could not only infect biological life forms but also induce what is known as a logic plague, infecting AI to do their bidding. After a conversation with the Primordial, who was under the influence of the Gravemind, Mendicant Bias turned on the Forerunners.

At the last minute, the Forerunners, with the help of a human named Chakas who was placed into the body of a Halo monitor named 343 Guilty Spark, activated the Halo array, killing all life in the galaxy and the Flood--except for the samples the Forerunners kept in storage. Eventually, the Ark began reseeding life across the universe, sending ancient humans back to Earth.

Several hundred thousand years passed, and the San'Shyuum had forgotten their ancient history with the Forerunners and began seeking out their technology again. Initially, they came into contact with the Sangheili (Elites), another alien race, and the sides formed an alliance known as the Covenant. The San'Shyuum, viewing themselves as prophets, led the Covenant with the goal of activating the Halo rings in order to ascend on The Great Journey. They seemed to be unaware this was essentially ritualistic mass suicide.

Meanwhile, humanity had also begun to spread out to the stars, founding colonies all over our little corner of the galaxy. And in the early 26th Century, civil unrest had begun to ferment, with the outer colony worlds believing that they were being taken advantage of for their resources, leading to a civil war between humanities' military, the United Nations Space Command, and the Insurrectionists.

In order to win the conflict, UNSC scientist Dr. Catherine Halsey decided to kidnap children, made clones that eventually died so their parents wouldn't worry, then raised them to be soldiers. The UNSC then injected them with drugs that killed half of them and turned the other half into super soldiers, also known as Spartans. Those kidnapped included a bigger-than-average redheaded boy named John-117, who would eventually earn the rank of Master Chief.

Finally, though, the Covenant encountered humanity, and seeing them as non-believers defiling the Forerunner technology, began a war to wipe us all out. This brings us, finally, to the first chronological game in the series, Halo Wars.


Halo Wars
Halo Wars

The Covenant began destroying human outer colonies, decimating the Insurrectionists as the UNSC desperately fought a losing battle while hiding the location of Earth from the aliens. On a colony world, Harvest, the Covenant found a Forerunner artifact that detailed the location of other Forerunner technology. The human ship The Spirit of Fire, under Commander James Cutter, followed the Covenant to the planet Arcadia. Once there, lead researcher Dr. Ellen Anders was kidnapped by the Covenant's Arbiter. (The moniker of Arbiter is a holy warrior title bestowed upon those who have been outcast and can only regain their honor in death.) Anders was forced to help the Arbiter find a Forerunner fleet hidden on a lost shield world, as only humans can activate Forerunner technology. Anders escaped, but not before she learned of the Flood, which managed to survive because of the lifeform samples left after the Halo array was activated.


Halo Reach
Halo Reach

Meanwhile, despite Spartan-II units like Master Chief helping to keep the Covenant at bay, the war was going badly, with Covenant forces continuously "glassing" worlds as they moved closer to Earth. At this point, the UNSC created the Spartan-III, a new iteration that no longer relied on kidnapped children.

A group of Spartan-III soldiers called Noble Team were sent to the planet Reach to put down some rebels, but the Covenant had begun invading Reach. Noble Team made a valiant effort to push the invasion back, but it realized it was hopeless. Instead of surrendering, the team evacuated Dr. Halsey via the Pillar of Autumn ship. Halsey left with the AI companion Cortana, as well as the Master Chief. Noble Team died and Reach was largely destroyed.


Halo: Combat Evolved
Halo: Combat Evolved

After its jump, the Autumn, commanded by Captain Jacob Keyes, found itself over Installation 04, the first Halo Array that humanity remembers encountering. The Autumn was attacked, forcing the crew to evacuate to the ring's surface. When Captain Keyes went missing, Chief searched for him, only to find the escaped Flood had spread to the ring itself and already began infecting human marines.

While searching for answers, the Master Chief came in contact with 343 Guilty Spark, the robotic floating orb who promised to solve the impending Flood threat via a tool called the Index and the Halo ring. Master Chief is assured that the Halo ring will kill both the Flood and the Covenant, but he isn't told it will also kill all sentient life in the galaxy to starve the Flood. Cortana manages to make contact with the Master Chief, who opts to self-destruct the Pillar of Autumn in order to destroy the Halo ring, and he escapes in a ship just before it's obliterated.


Halo 2
Halo 2

Following the events of the original game, the Master Chief arrived back on Earth, where his victory was briefly celebrated before the Covenant--having finally learned the planet's location--began a massive attack. Working alongside Sergeant Avery Johnson and Miranda Keyes--the daughter of The Pillar of Autumn's late Captain Keyes--the Chief pushed back the Covenant fleet and climbed aboard one of the ships, making his way to a second Halo ring called Installation 05.

The Master Chief intercepted the Prophet of Regret--one of three leaders who ruled the Covenant--and literally punched him to death in order to stop the ring from being activated. As he made his way further into the Halo array, the Covenant city-ship High Charity arrived and began a massive attack.

At the same time, another unexpected hero was on his own mission. A new Arbiter--given the title and sent on a suicide mission after failing to stop the Master Chief from destroying Installation 04--discovered the truth about the rings and realized the Prophets had been lying to the Covenant. Angered after Regret's death, the remaining Prophets replaced the Sangheili with the Brutes in their personal guard, and the Arbiter was betrayed by a Brute named Tartarus and left for dead.

Both the Master Chief and the Arbiter were captured by the Gravemind, who wanted to stop the ring from activating as it would kill him and all other Flood via starvation. Teaming up, the two succeeded, with the Arbiter killing Tartarus before he could activate the ring and the Master Chief taking off after the Prophet of Truth. However, Cortana was left with the Gravemind and the Ark was given the ability to activate all remaining Halo rings from one central location.


Halo 3
Halo 3

Two weeks later, the Master Chief returned to Earth and discovered that a transporter device buried in Africa is used to reach the Ark, with the Prophet of Truth intending to use it to activate all the Halo rings. While the Chief headed to the Ark in pursuit of Truth, a Flood-infested ship landed on Earth and the Flood gave chase. A brief truce was made between the Flood and the Arbiter-Chief duo in order to defeat Truth, who the Arbiter would go on to kill.

At this point, the truce between the Flood and both the Arbiter and Master Chief ended, and the Flood began attacking. They both made their way to the Ark and discovered that a new Halo ring is in construction that, if fired early, would not destroy all life in the galaxy, so they decide to activate it. This angered 343 Guilty Spark, as the firing would also destroy the Ark, prompting him to kill Avery Johnson before being destroyed by the Master Chief.

With the Ark set to fire the ring, the Master Chief and the Arbiter both escaped onto the Forward Unto Dawn ship and entered slipspace, but only half of the ship--the half carrying the Arbiter--returned to Earth. The other half, with the Master Chief in tow, remained floating in space for years, eventually drifting toward Requiem.

Activating the Halo ring prematurely succeeded in destroying the Flood along with the Gravemind, and it spared the galaxy at large. The Covenant and humans agreed to an uneasy peace, and a new Spartan program called the Spartan-IVs was created to deal with future conflict. And there would indeed be future conflict.


Halo 4
Halo 4

Several years after the events of Halo 3, the Master Chief was woken by Cortana as the Forward Unto Dawn approached a metal-cloaked planet called Requiem--the same planet created by the Didact thousands of years earlier. At this point, Cortana had begun approaching rampancy, a state of information overload that progresses via an AI's age.

Finding pockets of Covenant splinter groups on Requiem, the Master Chief was drawn to a location via a mysterious signal, as was the UNSC's Infinity crew. The UNSC believed the signal was sent by some sort of helper. Instead, the Chief was tricked into unlocking the Didact's containment prison, and the Didact began enacting his revenge on humanity by turning them into AI-driven Promethean warriors. A device called the Composer would allow him to do this from space, firing the weapon directly at Earth's surface.

In an attempt to save humanity, the Master Chief and Cortana--with help from UNSC Captain Thomas Lasky--confronted the Didact and attempted to detonate a nuclear bomb and destroy the Composer. However, the blast would have killed the Master Chief, so Cortana used her own power to transform into a hardlight shield, sacrificing herself but leaving the Chief unharmed.

With Cortana killed, Chief's moral center was lost. He reflected on his own status as a human versus a machine as a larger war began to brew.

Six months later, the crew of the Infinity remained on Requiem, attempting to stop the splinter Covenant faction from gaining a foothold. However, during this time, Dr. Halsey defected to the group, angered by humanity's treatment of her and intrigued by the promise of more Forerunner artifact knowledge. The remains of 343 Guilty Spark were also discovered around the same time, because of course they were.


Halo 5: Guardians
Halo 5: Guardians

Following the events of both Halo 4 and Spartan Ops, Catherine Halsey reached out to the UNSC again with information about recent attacks on outer colonies that appeared to use mysterious Forerunner technology. A newer Spartan-IV team called Fireteam Osiris--led by Spartan Locke--retrieved her and defeated the splinter group's leader, Jul 'Mdama, otherwise known as "Didact's Hand," as his Forerunner warriors turned on him.

During this time, the Master Chief had a vision of Cortana, presumed dead, who told him to head to the outer colony of Meridian. Desperate to locate his little blue friend, Chief set off against the orders of the UNSC, and Fireteam Osiris was ordered to locate and recover him. After a brief battle, Locke was defeated and the Master Chief escaped his clutches, heading next to the planet Genesis to reunite with Cortana.

Cortana claimed she had been cured of her rampancy and had gained control of the Forerunner's Domain knowledge database, as well as the massive Guardian constructs made to police the galaxy. Believing she had inherited the Mantle of Responsibility, she briefly trapped Master Chief and tearfully departed, then gained control of nearly every AI in the galaxy. Seemingly only a few were unaffected, including the UNSC Infinity's Roland, and the remaining heroes set off in search of a new technology called The Weapon to bring down Cortana. If the game's Legendary campaign is completed, another Halo ring is also seen as Cortana hums a cheerful tune.


Halo Wars 2
Halo Wars 2

One year after the events of Halo 5, the Spirit of Fire ship from the original Halo Wars was still floating through space--but the crew awoke to discover it had reached the now-Banished-controlled Ark. This collective, another splinter group under control of a Brute named Atriox, created an entirely new ring via the repaired Ark and planned to move it near Reach. In an ingenious move, the Spirit of Fire's crew planned to use the ring to get back home, but only Dr. Anders was able to board it before it jumped into slipspace--this left the crew to fight the Banished, during which time they discovered a new Gravemind growing under the Ark. Atriox destroyed this, but it suggested the Flood could still exist.

Got a news tip or want to contact us directly? Email

Join the conversation
There are 16 comments about this story