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. Throughout this article, comparative references to dates will be with respect to the approximate fictional time period 990.M41 to the end of 999.M41.

=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 Slann

Also known as the Old Ones, the Slann are an incredibly ancient race, vaguely reptilian in appearance, and thought to pre-date all other known corporeal species. The Slann 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. Reference is also made to the Slann in the Warhammer Fantasy setting 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 Slann. 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.

=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.

The Stellar Exodus

A poorly-understood period of history which is generally accepted to be the majority of mankind's initial forays into space and the genesis of most of the oldest Human colonies. This period is generally understood to lead into the Dark Age of Technology.

Dark Age of Technology

Again much of this era of human history 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 Age of Strife (M26-M30)
At an unknown point in the 26th millennium, humanity was nearing the end of a period of great success, the so-called "Dark Age of Technology"; this meant that human-kind had reached its technological peak. The "Standard Template Construct", or STC, had been perfected by human scientists and was being used on a large scale. Despite an apparent lack of central authority, humans inhabited vast portions of the galaxy, and their civilization was largely free from difficulties with external factions- namely, other races. This success was about to come to an end.

At that time, 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. This rampant corruption, which would eventually cause the Chaos God Slaanesh to be born, led to a great increase in Warp Storms. Parts of the galaxy inhabited by humans became isolated by these storms, leading to revolts and civil wars. Many human-inhabited systems also became prey to unfriendly alien forces, such as the Orks.

On Terra itself, human society degenerated as radiation storms caused a large amount of the population to degenerate into mutants and psykers. The lanscape of Terra was turned into a virtual wasteland, as techno-barbarians battled one another over the scraps of the ancient culture, and religious wars were an almost constant occurance. There is minimal background information about this time.

Mars underwent a very different transformation. After brief anarchy, the tech-priests of the Adeptus Mechanicus emerged victorious over the mutants and unified their homeworld. The Mechanicium devoted its time to studying the warp and after many lifetimes learned to detect 'lulls' in the warp storms. At the same time the immense fighting machines known as Titans were created. Whenever a break in the warp storms occurred, an expedition was sent, the successful ones establishing the Forge Worlds.

Rise Of The Emperor
Towards the end of the Age Of Strife, the Emperor emerged as a leader on terra. Employing genetically modified warriors that were later to become the first Space Marines, he united the warring tribes and through genetic modification was able to stabalise the human population, 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)
After many millennia of existing in decadence, the Eldar race had become so technologically advanced that the need for work and education became obsolete. This caused the breakdown in Eldar society as the vast majority of Eldar were focused purely on their own pursuits. The collective emotional presence of this decline caused a new power to be formed in warp. Sometime in the 30th Millenium the entity gained conciousness, creating the 4th god of the Chaos Pantheon, Slaanesh. It's birth created a massive warp storm, known as the Eye of Terror which engulfed the Eldar homeworlds and caused the death most of the Eldar race. The creation of the Eye of Terror also dispersed the warp storms surrounding Terra, allowing the occupants to take to the stars, and paving the way for the Great Crusade.

The Great Crusade (M30-M31)
The Great Crusade began 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. 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, expansion into outer space was slow, since the Emperor's armies were still small. In time however the Crusade gained momentum and countless worlds were reclaimed and united under the Emperor's rule. The Primarchs were also all found during this period, and took place at the head of 1 of the 20 Space Marine Legions.

After the campaign of Ullanor the Emperor stated that he would have to leave for 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 the greatest of the Primarches 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 entire Adeptus Astartes and Titan legions. The battle between the traitors and the loyalists was evenly matched and rent the imperium in two. At what seemed like the moment of utter defeat for the Imperium, the Emperor slew Horus and the forces of Chaos were routed

=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 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 man 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 an 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 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 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 Abbadon 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 the Imperium and the Xenos forces with Eldrad Ulthran dying in an attempt to recover a Blackstone Fortress which 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 millenium. 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.

The Necron Resurgence
In the late 41st mellenium the dormant Necrons have awoken to harvest 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 of the Warp or an Adeptus mechanicus Explorator fleet disturbing them, regardless the Necrons will reap havoc amongst the living races of the galaxy.

The Tyrannic Wars
cross-posted from Tyranids

The Tyrannic Wars are the collective conflicts ignited by the Tyranid race's sudden incursion on the galaxy, beginning around 745.M41 AD..

Hive Fleet Behemoth
As described in the rule book and the novel Warriors of Ultramar, Tyranids were first encountered by the Imperium in the Eastern Fringe of the Galaxy, near the planet Tyran. Adeptus Mechanicus scientists noticed several worlds that had mysteriously lost their biomass and atmosphere, then the scientists themselves disappeared. Later an Imperial Inquisitor named Kryptmann visted Tyran and found a data file with information on the Tyranids, left behind by the former occupants before their deaths.

Despite this, several planets were devoured by the Tyranids, but Kryptmann could not call for help due to the Shadow in the Warp. The Tyranids, now named "Hive Fleet Behemoth" by the Imperium, progressed further into human held areas of space, eventually reaching the Ultramar sector, the realm of the Ultramarines Chapter of the Adeptus Astartes.

Marneus Calgar, Chapter Master of the Ultramarines, recalled all his forces to the Ultramarines' homeworld, Macragge. Assembling a fleet and readying Space Marines on the ground, the Ultramarines face the Tyranid vanguard. Ultimately the Tyranids encircled and overwhelmed the planet Prandium - stripping its surface bare of life as an instrument to bring to mind tragedy for the reader, as Prandium had previously been described as a lush, green paradise of a world.

Ultimately, the Tyranids moved on to attack Macragge itself, and after a titanic struggle and great loss - including the heroic last stand of the Ultramarines veteran First Company, the Ultramarines prevailed. The Tyranids threatening Macragge were soundly beaten and retreated, while the influence of the Hive Mind faltered and the arrival of reinforcements, bringing hope for the Imperium. Imperial Navy spacecraft arrived at Ultramar, and the allies part company to renew their efforts in preventing the Tyranids regrouping. The final action against Hive Fleet Behemoth occurred in orbit of the gas giant planet of Circe, at the height of which the commander of the Imperial flagship, Admiral Rath, sacrificed the vessel with himself and all hands on board to destroy the Hive Fleet once and for all.

Hive Fleet Kraken
The second wave of Tyranids to fight against the Imperium was known as "Hive Fleet Kraken". Its arrival was heralded by a score of genestealer rebellions and insurrections on the Eastern Fringe. Instead of throwing one mass of troops against the human armies, this swarm split into countless smaller fleets, each one enveloping whole systems before reinforcements could arrive. Although this made each individual assault weaker and made some warp travel and communication possible, Kraken was attacking across a far vaster front than Behemoth. Two Space Marine Chapters based on the Eastern Fringe - the Lamenters and the Scythes of the Emperor - were all but annihilated. A vast portion of Kraken's strength attacked the Eldar Craftworld of Iyanden. Although eventually defeated, the attack killed four-fifths of the Craftworld's population; a terrible blow to the dwindling Eldar race.

As the fleet faced more severe resistance, smaller sub-fleets would combine to overcome it, narrowing the range of the Hive Fleet's attacks as it pushed further into Imperial Space. After the Ultramarines crushed a genestealer insurrection on Ichar IV, the Imperium's psykers were able to determine where the remainder of Kraken's strength was converging upon. Troops were rushed to Ichar IV ahead of the Tyranids. Marneus Calgar was elected Supreme Commander among the coalition of Imperial Guard, Space Marines and Imperial Agents, and once again led the Imperium to victory. According to Lieutenant Kage of the Last Chancers penal regiment, the Imperial Guard "Lost over a million men at Ichar IV". Kraken was not fully destroyed, and, after Ichar IV, split into several splinter fleets. Although tiny by comparison, they pose a threat to isolated or poorly defended worlds, and have slipped far beyond the cordon established to combat Kraken.

Hive Fleet Leviathan
Less than ten years after the defeat of the Kraken, Lord Inquisitor Kryptmann noted the tell-tale signs of yet another Tyranid invasion. He implemented the Kryptmann census, burning out dozens of astropaths in the attempt to contact scores of worlds on every fringe in the Imperium. Slowly, the responses - and lack of them - formed a pattern, and the venerable Inquisitor was able to chart the path of the Tyranid's latest hive fleet. Codenamed 'Leviathan', this time the Tyranids were approaching from below the galactic rim, attacking from two points spaced wide apart in the shape of a closing pair of jaws, cutting off large portions of the galaxy from warp travel or astropathic communication. At a great cost in human life, a combined force of PDF troops, Ultrmarines and Deathwatch under the command of Inquisitor Kryptmann crushed the left 'half' of Leviathan on Tarsis Ultra, destroying the Tyranids nearest to Holy Terra, and reestablishing astropathic contact with the worlds between Leviathan's jaws. The Imperium had won its first victory, but Leviathan's path continue. Perhaps Leviathan's main gain was the vital forge world of Gryphone IV, home of the War Griffons Titan legion. Kryptmann knew he had to slow down the hive fleet's advance to buy time for Battlefleets Solar and Tempestus to muster. With grim finality, he ordered a cordon to be established. Every world within was to be evacuated and undergo immediate exterminatus wherever possible. With one stark, callous decision, the Inquisitor had inflicted the Imperium's worst act of genocide upon on its own since the Horus Heresy. Kryptmann was denounced as a radical and a traitor; when migrating Orks claimed a score of former human worlds, he was stripped of his title and thrown out of the Inquisition.

Yet Kryptmann still had loyal allies within the Deathwatch, and incepted a plan to halt Leviathan without the loss of further human life. Using a brood of captured live genestealers, the Inquisitor engineered a mass infestation within the Ork-held Octavius system, very close to Leviathan's advance. The signal soon drew the entirety of Leviathan into the tight cluster of Ork systems. The plan had worked, and both races - as reported by astropaths still loyal to Kryptmann - are involved with destroying each other, with each side exhausting the strength of the other without a clear victor in sight. One thing is certain: each race thrives on war, and whichever side wins, the Imperium shall have to face a potential threat far greater than before.

A shadowy council within the Imperium called the Strategic Collective has been analysing all details of the Tyranid's invasions, and have drawn a conclusion as stark as it is terrifying: the fleets faced by the Imperium to date are but parts of a far greater whole, and this whole will be arriving at the Imperium's borders within less than a century. They estimate that mobilisation levels will need to be increased by a minimum of 500% - effectively including every able-bodied man, woman and child on every world in Segmentum Solar, Obscurus and Tempestus - to have even the nearest hope of slowing down the Tyranids.

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