Setting:Brighthammer 40,000/Timeline

(This is a Brighthammer 40k Second Edition article.)

Unknown:

• The first sapient species start appearing in the galaxy. Among them are the C'Tan, the Star Children who live within suns.
• The terrible Great Old Ones roam space, enslaving and modifying species on their whim. Their evil spawns the first Warp Horrors.
• The Necrontyr make contact with the C'Tan and become a transhuman species.
• The Great Old Ones, bolstered by their mastership of the material universe begin to turn their attention towards the Warp. They begin to exercise control over the various Horrors, forming corrupt Warp Gods that thrive on harshly enforced worship of the slave races.
• The War in Heaven: The Necrontyr and C'Tan fight the Great Old Ones. The C'Tan flee into hibernation and the Necrontyr are likewise scattered and beaten.
• Critically weakened, the Great Old Ones are subject to a massive slave uprising. Siding with the slaves are some of their own Warp gods, who later take on the identity of the Lords of Order.
• Lord Kroak, their Enlightened Supervisor, sends the last handful of his species into the darkest corner of the galaxy before he, too, is forced into hibernation. The Great Old Ones are finally defeated in the Materium.
• The Immaterium, bristling with the hatred of the dead Old Ones and the slaves that perished, forms one last Warp Horror out of the loyalist Warp Gods, The Universal Destroyer, against which even the assembled armies are helpless. Only the ascension of the Ork brainboyz Gork and Mork stops the Destroyer from outright collapsing the entire galaxy.
• The War of Souls: The Destroyer and his adversaries wage war in the Warp for millenia. Spacetravel becomes nearly impossible.
• During the long darkness in the galaxy, the Initates of Order - originally a warrior brotherhood during the rebellion - reform on countless worlds.
• The Enslavers, minor manifestations of the many-bodied Destroyer, burst forth through into the galaxy and kill entire worlds.
• Three Lords of Order begin to take their modern form as result of the work of the Initiates. Eventually, as the Enslavers that had crossed into the Materium are thought annihilated the warp becomes usable again (although still dangerous).
• The Eldar Ascendancy forms.

12000 BC

• The Universal Destroyer begins harvesting the souls of unprotected Psychers.
• The first Ork Empires form.

8000 BC

• At the end of the last Ice Age, the Emperor of Mankind is born in central Anatolia.

M2

• A ruinous global wars leaves the human nation states in ruins. Humanity creates one united government, the Terran Alliance, to prevent the divisions of the past from resurfacing.
• Terraforming of Mars begins under a multinational conglomerate which eventually evolves into the first truly global corporation.

M15

• Age of Exodus: The Terran Alliance begins colonising distant worlds via sleeper ships.
• Mars begins its specialisation into a purely industrial world. Eventually, it evolves into the vital point for manufacture to support outlying colonies further out into the solar system.

M18

• The Emperor of Mankind defeats the C'Tan known as the Void Dragon on Mars, forcing technological secrets out of him.
• Thusly, humanity develops the Warp Drive and the Geller field.
• Drained by the battle, the Emperor falls into a regenerative coma that will last 10,000 years.
• After countless millenia, human Psychers are being born again.

M19

• The Dark Age of Technology: Unguided by the Emperor, whisperings of the Void Dragon drag humanity into the abyss of transhuman advancements.

M25

• The Golden Men (the followers of abstract transhumanism) declare An End to Flesh and starts a civil war that destroys the Terran Alliance. Opposing them, the Iron Men take up the flag of humanity. Thus begins the Human Age of Strife.
• The Universal Destroyer, bloated on the spirits of countless Psychers, tears into the Materium again. Spacetravel is again rendered impossible, starting the Galactic Age of Strife. An entire sector of space is destroyed outright; it has since been known as the Void.*
• The Elder Ascendancy begins a concerted effort to create a fourth Lord of Order, the Lord of Passion. While some Eldar only join the effort to finally get rid of the Destroyer, most are genuine about bringing peace to the galaxy.

M26

• Large parts of the the Initiates of Order reforge themselves into the Adepts of Unified Order and begin a crusade to convert whole worlds to their worship of the three Lords.

M28

• The Emperor reawakens on destroyed Terra. He sheds a manly tear before bringing the local civil war to an end.
• Next, the sends the Void Dragon into hibernation.
• The Emperor's rule begins to slowly extend to the closest solar systems, those reachable with slower FTL methods than direct warp travel.

M30

• The Eldar create the Lord of Passion, Slaanesh. Most of them ascend, except for the Bright Eldar (who are rejected as being too impure, but continue to study the means of ascension) and the Exodite Elder (who never liked the idea to begin with).
• The Universal Destroyer is finally overwhelmed by his opponents and its composite Warp Gods are forced apart and sealed. Most succumb to lack of worship, but some endure.
• The Exodie Eldar make it their mission to subdue pieces of the Destroyer to gain power in the Materium.
• As the Warp calms, botht he Adepts of Unified Order and the new Imperium of Man begin to integrate the wayward human colonies into their respective realms.
• The Emperor begins his Primarch project, creating 20 superhumans with his genes. Thanks to sabotage by immaterial sources, they are spread throughout the galaxy.
• While searching for one of the missing Primarchs, first contact occurs between the Adepts and the Imperium. While the Primarch Sanguinius is recovered, the encounter ends in bloodshed, war is declared soon afterwards.
• The Adeptus Maximus declares the Imperium of Man a heretical abomination, the Imperium in response starts fielding the first Space Marine legions during The Great Crusade.

M31

• After many long and difficult battles, the fleets and armies of the Adepts are decimated, but the Lords of Order themselves begin to affect the Materium to support their worshippers.
• Sensing a solution that will not require untold millenia of bloodshed, Horus the Great and several of his fellow primarches ritually sacrifice themselves to ascend into the warp.
• While himself an atheist, the Emperor declares the Initiates of Order an accepted religion. Many more religions follow.
• The last remaining Adepts are reintegrated into the Initiates. The Great Crusade ends.

M32

• Due to many outside forces acting upon the Imperium, the disparate nature of many of it's worlds often acting against one another, and endless low level conflict with the many aliens and remaining Initiate dissenters, the Emperor's Secret Service is formed to deal with matters before they flare into war. They are granted great power and authority due to their position, and the importance of their job.

M36

• The Imperial Secret Service records the first known conflict between the Exodite Eldar and a species of amphibians called the Slaan. Further battles between these two adversaries continue with disturbing regularity over a selected few worlds. Further search of local archives point to conflicts leading back before humanity's recorded history. The Secret Service is tasked with disrupting such engagements and collecting whatever is fought over. Most of what they recover is ordered sealed.

M39

• The Slaan track down some of the Great Old Ones and reawaken them. Soon, covert operations to reassure galactic control are begun.

M40

• Rise of the Tau Empire. Declaring the Elder, Imperium, Orks, and Initiates a great evil on the galaxy, the Tau (led by the Ethereal Caste, which suddenly appeared several centuries prior) embark on a mission of enforcing The Lesser Evil, a unification under their rule.

M41

• First contact with an extragalactic species. The Zoanthropes raid the Klendathans' (a semi-indepedant human civilisation) worlds for genetic material. Contact ends as suddenly as it began. It is only realized why when a Klendathan scout makes contact with a pursuing species above the world of Tyran.
• The conflicts with the Tyranids shocks most galactic powers into an uneasy alliance, as the sheer scale of the threat becomes known.