Timeline of the Warhammer 40,000 Universe

''This is an article about the fictional setting of the Warhammer 40,000 games systems and their derivatives. For a discussion of the games systems themselves, please refer to Warhammer 40,000''

Games Workshop has provided a rich background story to its Warhammer 40,000 setting. All the models within the Warhammer 40,000 range are created within the context of the fictional setting, and revisions in canon, which have occurred often, have led to some models becoming unusable within the official rules of the game. The following article represents the current canon storyline. This article relates to events in the universe prior to the late 41st Millennium in the Warhammer 40,000 setting.

All dates will be stated using the Imperial Dating System, which is used in most canonical sources to specify dates of events, in which the standard syntax is a 3 digit number representing the last 3 digits of the year, and then the millennium. As an example, 345.M31 represents AD 30345.

=Pre-History=

The prehistoric era of the Warhammer 40,000 universe occurs many millions of years before the present day, and provides a context for some of the recent plot devices introduced in the 41st Millennium setting. Prehistoric backstory is exclusively written from an omniscient past-tense perspective, to emphasise the fact that it truly is the 'past' and not the primary setting of the wargame.

The Old Ones
The Old Ones were an incredibly ancient race, and thought to pre-date all other known corporeal species. The Old Ones are commonly thought to have sustained advanced technological development in excess of sixty million years ago and are implied as being responsible for the creation or advancement of most of the currently active species in the current era, although Humanity was the only species that was left untouched by them (Though there is some suggestion that Humanity was created by the Old Ones but since their defeat by the C'tan and the Necrons, Humanity had to evolve on its own). Reference is also made to the Old Ones in the Warhammer Fantasy setting (in particular in reference to the Lizardmen culture) and the relation between the two is unclear.

The War in Heaven
The War in Heaven is a past setting featuring a great conflict that arose between the C'tan, immensely powerful, incorporeal beings existing only in the material universe (unlike other races which have a presence both in the warp and in the material universe), and the Old Ones. This conflict is related in Warhammer 40,000 fiction by the Eldar, as it forms part of their myths and legends and is virtually unknown to most other races. The end result was the defeat of the Old Ones, after which the C'tan and Necrons went into hibernation as the lesser races (and primary food source for the C'tan) were being killed off by the Enslavers.

=Ancient History=

Ancient History is the period in the timeline in which Humans are documented as being active - from around the present day (early Third millennium AD) - ending with the internment of the Emperor and the end of the Golden Age.

Human Ascendancy
This point in the timeline of the setting is concerned with events close to the real world in the present day, and is left purposefully unclear. During this time the Emperor used his ancient wisdom and psychic power to guide humanity in a direction that would benefit everyone, but kept himself in the background, pledging to only take the lead in Humanity's darkest hour.

The Stellar Exodus
A poorly understood period of history which is generally accepted to be mankind's initial foray into space and the genesis of the oldest human colonies. Expansion outside the Solar System was at first painfully slow, generations living and dying on the long interstellar voyages.

Dark Age of Technology
With the development of the warp drive and then the mutant human Navigators, mankind was able to expand at an unprecedented level through the galaxy. This era of exploration is said to have brought new ideas, wealth and arrogance, beginning the Age of Technology. Much of this era is mysterious, but what is known (largely from the works of an apocryphal character, Keeper Cripias) is that a group known as the Golden Men relied on the works of another, the Stone Men, in order to create a fantastically prosperous society, but one devoid (by later Imperial standards) of spirituality or piety. The Stone Men are said to have created a third group, the Iron Men, postulated by fans to be androids with true artificial intelligence, in order to assist them. The Iron Men became uncontrolled, and a cataclysmic conflict broke out, resulting in a partial Malthusian Catastrophe. The war that erupted between humans and androids is implied as having been on an unimaginable scale, so great that even after tens of millennia the Imperium still has a prohibition against artificial intelligence in place.

The appearance of psykers within humanity heralded the end of the Age of Technology.

The Age of Strife (M26-M30)
During the so-called "Dark Age of Technology," humanity had reached its technological peak. The Standard Template Construct, or STC, had been perfected by human scientists and allowed unprecedented expansion of humanity throughout the galaxy.

As humanity became widely dispersed during the Age of Technology, the ancient Eldar Empire began its decline; the great success of the advanced Eldar race had led to decadence and hedonism on a great scale. Within the psychic universe of the warp, the spiritual corruption of the Eldar civilisation was reflected in the forming of a new Chaos god, in turn causing massive disturbances in the warp; parts of the galaxy became isolated by these warp storms, making warp travel and communication impossible, cutting off many human worlds, including those of the Solar System. The Age of Strife followed the Age of Technology, as human civilisation collapsed in widespread insanity, daemonic possession, anarchy and inter-human war. Terrible weapons of the golden age of technology were unleashed, devastating many human colonies and turning verdant worlds such as Baal Secundus into irradiated desert planets. Many isolated and vulnerable human-colonized worlds also became prey to hostile alien races, such as the Orks.

Terra and the rest of the Solar System was surrounded by terrible warp storms, isolating the human home world for several thousand years. By the 28th Millennium almost all traces of civilization on Terra were long gone; instead, techno-barbarians battled one another over the scraps of the ancient culture.

Rise of the Emperor
Towards the end of the Age of Strife, the Emperor emerged as a warlord on Terra. Employing genetically modified warriors that were later to become the first Space Marines, he united the warring factions of Earth, and made plans for reconquering the galaxy. It was during this period that the Primarchs were created and subsequently lost.

The Fall of the Eldar (M30)
As Eldar civilisation degenerated into hedonism and excess, a new power began to take form within the psychic universe of the warp. Sometime in the 30th Millennium the entity finally gained full consciousness, becoming the fourth god of the Chaos Pantheon, Slaanesh. Its birth overwhelmed the extent of the Eldar spacial empire in Chaos, creating the warp/real space overlap known as the Eye of Terror. With the birth of Slaanesh, the warp storms surrounding Terra abated, allowing the Great Crusade.

The Great Crusade (M30-M31)
The Great Crusade was a brief age of rebuilding and reunification, beginning as the Age of Strife came to an end. The warp storms isolating human worlds had finally disappeared, and the Emperor was ready with his Space Marines and Imperial Army to begin the reconquest of the galaxy. The Emperor and the Mechanicum of Mars struck an alliance, which allowed the Emperor's forces access to improved wargear, Battleships and Titans, and allowed the expansion outside the solar system, and the reclamation of the human inhabited worlds colonised during the Stellar Exodus.

At first, the Emperor's armies were still small and the Crusade's progress was slow, but with each conquest the Crusade gained more momentum as new warriors joined the struggle. The Primarchs were also recovered during this period, each taking command of one of the twenty existing Space Marine Legions. With the help of the Primarchs, the Great Crusade swept across the galaxy. Human worlds were freed from alien dominance and Chaos was banished back into the warp.

After the campaign of Ullanor the Emperor stated that he would return to Terra to begin the next phase of his plan, and Horus was declared Warmaster, de facto leader of all the Emperor's armies. The Imperium continued to expand until the Horus Heresy.

The Horus Heresy (M31)
Eventually Horus fell to Chaos and attempted to destroy the Imperium from within. The treason of Horus spread to embrace around half of the Imperium, from small planetary defence forces, right up to nine Space Marine Legions and several of the Titan legions. The Civil conflict culminated in a massive siege of the Emperor's Palace on Terra. After 55 days of fighting the war was ended by The Emperor and Horus dueling in single combat aboard Horus' flagship. Although mortally wounded, the Emperor was able to strike down Horus. The Chaos Legions retreated to the Eye of Terror, and the crippled body of the Emperor was instated into the 'Golden Throne'.

=Modern History=

The Age of the Imperium (M31-M41)
The Age of the Imperium is the setting of most of the works of fiction that describe the Warhammer 40,000 universe, and is typically referred to in the present tense. The approximate time period begins in the 31st Millennium, and continues as Games Workshop continues to release additions to the game. The Age of the Imperium is generally conveyed as spanning from the end of the Heresy to the narrative present - a space of approximately ten thousand Terran years.

Occasional 'historical' settings are related in Games Workshop publications, such as 'historical refights' or game scenarios based around events happening some time before the current time frame, but much later than the events of the Heresy. These settings still very much fall under the Age of the Imperium, as most of the organisations and cultural norms (and even some of the individuals) exist in both these and 'present' times.

The Birth of The Imperium (M31)
In the immediate aftermath of the Horus Heresy, the empire underwent a massive structural reform in organisation to minimise the risk of future catastrophes. In the absence of the Emperor, power was shifted to the High Lords of Terra, and the Imperial Army was split up into the Imperial Guard and the Imperial Navy. The Inquisition was also formed during this time. The Space Marines also underwent structural reform under the guidance of Roboute Guilliman, the main change being the Legions being split into one thousand-strong Chapters. The structure of the Imperium has since remained in this state.

The Age of Apostasy (M36)
The Age of Apostasy is an era of civil war and considered to be one of the bloodiest eras of the Imperium after the Horus Heresy.

An insane tyrant, Goge Vandire, became both Ecclesiarch and High Lord of the Administratum through bribery, blackmail, coercion and murder. Vandire started a period of time known as the Reign of Blood where multiple wars of faith were fought as Vandire attempted to gain control of the Imperium.

The Reign of Blood took 70 years before a messenger delivered the news that heralded the end. On the world of Dimmamar, a man named Sebastian Thor and his sect, the Confederation of Light, denounced Vandire as a traitor. As an accomplished orator, Thor was able to sway millions to his cause.

Eventually Vandire was besieged on Terra by several Space Marine chapters, and several Imperial guard loyalist regiments. The Space Marine fleet sent down a massive bombardment which caught most of the traitors in the open. Lord Vandire was killed by his bodyguards, the Brides of the Emperor. In the aftermath the Ecclesiarchy was reformed, and the Brides of the Emperor were reformed into the Sisters of Battle, the militant arm of the Ecclesiarchy, with strong operational ties to the Ordo Hereticus.

The Black Crusades (M31-M41)
A Black Crusade is a term used to describe a number of mass incursions by Chaos Space Marines into Imperial Space. The most prominent of these are crusades led by the Black Legion Warmaster Abaddon the Despoiler.

The 12th Black Crusade
The Gothic War is the common name for the wider conflict stimulated by Warmaster Abaddon's twelfth Black Crusade (Chambers 1999), which spanned the dates 139-160.M41. The conflict was fought almost entirely around the Gothic sector of Imperial space. The 21-year war resulted in millions of casualties, at least one Imperial world completely obliterated, many ships destroyed and many important personalities killed or incapacitated. Most significantly, the events of the Gothic War revealed the true nature and purpose of the ancient spaceborne alien artefacts known to the Imperium as the Blackstone Fortresses. It is this conflict which provides much of the background setting for the game Battlefleet Gothic.

The 13th Black Crusade
The 13th Black Crusade is the most recent of the incursions against the Imperium by Abaddon the Despoiler, and served as the basis of Games Workshop's 2003 summer campaign. Every race playable in the game fought in this Black Crusade, including the Tau, who used the re-deployment of Imperial forces to initiate the Third Sphere Expansion of their empire. The war had massive casualties amongst both the Imperium and the Xenos forces, with Eldrad Ulthran dying in an attempt to recover a Blackstone Fortress that had been used to devastating effect in space. In the end, the forces of Chaos were forced into a stalemate with Battlefleets Obscuras, Solar, Gothic and Pacificus retaking control of the Cadian Gate.

=The Present=

This refers to events that occur during the period in which Warhammer 40000 is set, most primarily the 41st millennium. The events are often used as inspiration for summer worldwide campaigns, with the results of the campaign influencing the background material released after the campaign.

Emergence of the Tau Empire (M37-M41)
In the late 37th millennium the Tau race was united under the doctrine of 'The Greater Good' and underwent a rapid technological advances and a large expansion into colonisation of space. The Imperium only came into contact with the Tau in the 41st millennium and thus the number of conflicts they have been involved in is minimal compared to other more numerous and widespread species.

The expansion of the Tau also caused several species to be incorporated into its ranks, such as the Kroot and the Vespid. In games these are usuable as Tau allies.

The Necron Resurgence
In the late 41st Millenium the dormant Necrons have awoken to renew their harvest of the living races of the galaxy for their masters, the C'tan. The cause of the Necrons awakening from their long sleep is debatable, with several theories being that the Tyranids' Shadow in the Warp or an Adeptus Mechanicus Explorator fleet disturbing them.

The Tyrannic Wars (745-999.M41)
The Tyrannic Wars are the collective conflicts ignited by the Tyranid race's sudden incursion on the galaxy. . Three major Hive Fleet incusions have been described thus far, called Behemoth, Kraken and Leviathan respectively.

Ongoing
Games Workshop continues to recount the ongoing history of the Imperium through periodic campaigns. There are no current campaigns.

=References= Chambers, A.; Thorpe, G.; Johnson, J. (1999) Battlefleet Gothic, Games Workshop. ISBN 1-869893-65-4 Chambers, A.; Thorpe, G.; NcNeill, G.; Bishop, S. (2001) Codex:Tyranids, Games Workshop. ISBN 1-84154-013-7 McNeill, G. (2003) Warriors of Ultramar, Games Workshop. ISBN 0743443527