‘Halo’ Mythology and Timeline Explained: What You Need to Know Before Watching the Show

We run down the complicated history and timeline of the “Halo” games in advance of the Paramount+ adaptation


Video game lore is, more often than not, a healthy blend of fun and overwhelming. And for a series like “Halo,” which has yielded 16 games over 20 years in addition to a healthy glut of spin-offs, this is double – maybe triple – the case.

With the highly-anticipated Halo TV series premiering on Paramount+ on March 24, it is now more important than ever to familiarize yourself with the mythology of the games – or at least brush up on it. And if that sounds like an impossible task, don’t worry – we’ve got you covered!

Here’s everything you need to know about the “Halo” universe ahead of watching the show.

The Era of the Precursors and Forerunners

Forerunner in “Halo” Games (Bungie)

In order to properly dig in to the “Halo” universe, we first have to travel back millions of years before the games even start. In 15,000,000 BCE, an alien race called the Precursors reigned control over the universe. During their rule, they appointed a human-like species called Forerunners to protect the universe against interspecies conflict.

The Forerunners enjoyed their tenure for five million years, until the Precursors decided to pass their responsibilities on to ancient humans. The Forerunners did not take this well, and (over?) reacted by initiating a war with the Precursors and driving them out of the Milky Way. The area where the Precursors landed was desolate, and resources were scarce. So in an effort to preserve themselves, they transformed into dust (as we all would, right?). With the Precursors gone, the Forerunners retained control over the universe, establishing a tyrannical hierarchy of races.

Meanwhile, the Precursors’ dust became infected by the anger they held toward the Forerunners. 10 million years after the dust formed, humans began to unwittingly feed it to their animals, which turned their adorable pooches into evil little Cujos. In an attempt to escape the corrupted dust, which they referred to as “the Flood,” the humans started a battle with the Forerunners. The Forerunners had not yet seen the Flood, however, and assumed it was an excuse made up by humans to pick a fight. The war went on for awhile, with the Forerunners eventually winning and forcing humans to return to a primal caveman state as punishment.

After having won the war against the humans, the Forerunners finally became aware of the Flood, but were sadly unable to defeat it. So instead, they created a network of giant circular weapons called the “Halo Array,” (the titular halos!) which would supposedly eradicate any and everything that the Flood could thrive on. The Forerunners knew that, ultimately, they too would be wiped out by Halo, so they left behind little capsules that might one day grow into new life.

The Founding of the Covenant

Covenant Aliens in “Halo” (Bungie)

Thousands of years later, around the year 2525, humanity has evolved beyond their primal state. During their evolution, a new alien race called the ‘San’Shyuum’ or ‘Prophets’ also evolved, comprising devout religious fanatics who see the Forerunners as their Gods. The Prophets’ cult-like leadership allows them to sustain power over a number of different species, such as the robotic Unggoys and Sangheilis.

Together, the species formed a pact called “the Covenant,” the intention of which is to exact power over the Halo Array and eventually fire it off.

The Human-Covenant War

Master Chief in “Halo” (Bungie)

As they both venture through space, the humans and the Covenant eventually encounter one another and enter into battle, because the latter sees the former as an affront to their gods. One of the Covenant’s first targets is humanity’s largest military-hub, a planet called “Reach,” home to a super-group of soldiers called the Spartans. After successfully invading, the Covenant pushes the humans off of Reach and establish it as their own.

Among the humans pushed off of Reach is Master Chief Petty Officer John-117, or “Master Chief,” the commander of the Naval Special Warfare Command, and the protagonist of the “Halo” games. Following the arrival of the Covenant on Reach, Master Chief and his AI sidekick, Cortana, flee Reach on a spaceship called the Pillar of Autumn. The ship is quickly hunted down by the Covenant, and, as a response, randomly plunges itself through time and space. (This is where the game’s action really kicks into gear.)

Autumn conveniently arrives at one of the Halo rings – Installation 04 Halo – and is followed there by that pesky Covenant. The latter attacks and kidnaps Chief’s captain, Jacob Keyes. Chief narrowly escapes the ship via an escape pod and lands on the Halo ring, where the Covenant follows him. There, both species discover the malevolent Flood. Halo’s caretaker, 343 Guilty Spark, pairs up with Chief to protect the ring against the Flood. The ever-heroic Chief ends up saving the day by blowing up the Autumn, destroying the Flood and the Halo Ring in its wake.

The Halo Array

Halo Array in the “Halo” games (Bungie)

Back on a space-station near earth, Master Chief is recognized as a hero for eradicating the Flood. Not soon after his return from the mission, however, it becomes clear that the human-Covenant war is far from over, when the alien race attacks humanity once more. In an effort to put an end to the conflict, Master Chief follows Covenant through a glitch in space, only to find himself on yet another Halo ring.
Once on the ring, Master Chief realizes that the Covenant are trying to mobilize and gain control of it. He is joined in his effort to stop them from wreaking too much havoc by a Covenant member called the Arbiter, who hopes to prevent his race from simply following their leaders blindly, much to the disdain of Tartarus, the Covenant’s chieftain.

Master Chief, the Arbiter and the human Sergeant Avery Johnson form an alliance, and return to Earth to defend humanity against the Covenant. While working defense, a spaceship replete with Flood particles lands on Earth. Now, the pair are tasked with not only stopping the Covenant from activating every Halo ring from an installation called the Ark, but also with protecting humans against the Flood.

Master Chief embarks on a mission into space to protect humanity against the Covenant. When the Covenant descend, he and Cortana are forced to crash-land on a Forerunner planet called Requiem.
On Requiem, Master Chief unwittingly disturbs the Promethean Forerunner Didact, the commander of the species’ military. Didact attacks Master Chief, and Cortana sacrifices her life to protect him.

Or does she? In a later game, we find out that she did not die, and instead became immortal by unlocking the Forerunner’s Domain. With this newfound power, she strives to become the ruler of the universe. Master Chief attempts to stop her, but cannot, and all species are forever subject to her command.

Whether the Paramount+ “Halo” series will follow any of this mythology closely is still unknown, but the show has already been renewed for a second season so there’s plenty of story left to tell.