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 A.D.) - 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

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.

However, by far the worst event of this period for humanity was the spectacular rise in the occurrence of human mutation, especially the mutation leading to psykers and the psychic powers they wielded. Prior to this, humans had had little experience in dealing with the forces of the warp, and the unexpected appearance of humans who could draw upon its energies led to riots, witch hunts and lynchings. Many psykers themselves were driven insane, either by the great power they suddenly possessed, or by the fear of persecution (or both).

Many psykers were overwhelmed by Chaos entities, and were possessed. These possessed psykers, as well as other selfish (or insane) psykers who learned to control their power, would cause even more havoc, leading to mass hysteria and devastating wars. Horrific weapons invented previously during the era of technological achievement were unleashed, turning verdant worlds such as Baal Secundus into barren, irradiated desert planets- or worse.

In a relatively short span of time, the galaxy-spanning human civilization was brought to its knees, and was forced to endure nearly five millennia of terror, war and slavery. Other than tales of great suffering, little information has survived this dark time.

During the first half of the Age of Strife control of the Sol System shifted constantly between Earth, Luna and Mars. By the 28th Millennium all traces of civilisation on Earth were long gone; instead, techno-barbarians battled one another over the scraps of the ancient culture. Little information remains from this dark time, but it is known that tyrants such as Kalagann of Ursh (northern Asia/Russia), Cardinal Tang, and Narthan Dume of the Panpacific Empire ruled during this age. According to the novel Horus Rising by Dan Abnett, Dume was opposed by the Yndonesic Bloc, while the Urals remained a centre of industry.

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 tech-priests then visited Earth but were appalled at the destruction there and saw nothing worth saving. Instead, the Martians studied 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.

For over a thousand years the Cult Mechanicus watched and waited. Whenever a break in the warp storms occurred, an expedition was sent, complete with a full Titan Legion and thousands of servitors and tech-priests. Some of these expeditions were lost in the warp or died on faraway worlds. Others succeeded in establishing 'Forge Worlds' - replicas of Mars. Broken messages were transmitted to Mars, but it was not until the time of the Great Crusade that the Forge Worlds and Mars would be reunited.

The Fall of the Eldar
After many millennia of existing in decadence, the ancient race known as the Eldar had become so technologically advanced that the need for work and education became obsolete. Two groups of Eldar became known, one of which was diligent, strong and honorable, but the other side which was decadent and murderous. The latter were so involved in their own wants, they became deprived of morality, engaging in acts that would make most serial killers of today look sane. Unlike humanity and most sentient races, however, the Eldar have an immense presence of emotion in the warp. When they began to prey on their own species and engage in these acts, the impending emotional cocktail burst forth from the warp, creating the dark-god Slaanesh. Ripping a hole in the material universe, now known as the Eye of Terror (in what was previously the center of Eldar civilization), Slaanesh feasted on the souls of the Eldar within thousands of light years. Their population was greatly reduced: the survivors created the giant craftworlds, vast city-ships, and the Eldar became a race totally dependable on their "path" in life, sticking to their rigid adherence to their code of honor, lest their emotions lead to another disastrous catastrophe.

The Great Crusade
cross-posted from Great Crusade

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. Making a pact with the Priesthood of the Machine God on Mars, the Emperor promised to spare their lives (the Emperor despised their use of bionics and religion as being against what the Great Crusade stood for) so long as they aided him in his mission to reunite humanity. The Emperor was a man of science and technology, and so in him many saw the coming of the Omnissiah that had been prophecised. The Mechanicum pledged their support, and the symbol of the Imperium changed from the lightning bolt to the double-headed Eagle, to symbolise the union of the Empires of Earth and Mars. With the forge factories and mechanical output of Mars, the Emperor was able to refit his armies, and more importantly, he now had the use of the Titan Legions, formidable war machines with the potential to dominate the battlefield.

At first, expansion into outer space was slow, since the Emperor's armies were still small, and more importantly his Space Marine legions were inhibited by the lack of their Primarchs, which made the production time for a Space Marine much longer. However, this was to end, as on Cthonia, a planet in a system not far from Terra, the Emperor for the first time was reunited with one of his Primarchs, Horus. Having been discovered at an early age, the Emperor took Horus under his wing, and taught him all he knew. Horus and the Emperor had a truly unique bond, and many times they saved each others lives. But after 30 years, the Emperor discovered another of the Primarchs. Although Horus was pleased at the discovery of one of his brothers, he secretly pledged to always be the Emperor's most loyal.

Through time, all the primarchs were found, and each was placed in command of their legions. The legions as a result were massively expanded with new recruits from their primarchs adopted homeworlds, and space marines could now be produced within a year. But this acceleration produced fundamental defects within the psyche of each space marine which was later to prove fatal.

After the campiagn of Ullanor, the Emperor claimed it as the greatest victory of the Imperium to date, and that Horus should be given credit. Hailing Horus and his legion, the Emperor stated that he would have to leave for Terra to begin the next phase of his plan, and that in his place Horus would be declared Warmaster, de facto leader of all the Emperor's armies. Although Horus was troubled that the Emperor should leave him, with him as their new commander, the Imperium continued to expand ever outwards, and this situation lasted until the Horus Heresy.

The Horus Heresy
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 Gothic War (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.

Early Raids

The action begins as described in the Battlefleet Gothic book with (presumably Abaddon's) forces raiding a monitoring station on the isolated world of Arx. The protagonists in the book however do not appreciate the significance of this event until further attacks on outposts and shipping throughout Segmentum Obscurus reveal a pattern; mutilation of victims, in some cases the presence of unusual and severe fungal infestations, and not a single attacker - or corpse thereof - recoverable or even evident. It is suggested in the account in the book that the rumours among Naval crew of the reappearance of the Chaos warship Plagueclaw were both true and connected to at least some of the attacks. This is proved obvious when Chaos Space Marines of the Death Guard legion are held responsible for attacking the Morganghast hive world.

Typical to many of Games Workshop's portrayals of emerging galactic conflicts, the account then speaks of warp storms increasing in activity around the Gothic sector and a corresponding increase in unrest of Imperial citizens. This kind of activity in the setting is almost always used to set the scene for a war with Chaos forces and, true to form, the next few paragraphs detail a mounting sequence of strategic attacks by Warmaster Abaddon's forces against targets known - to both he and various protagonists on the Imperial side - through myths and ancient, vague records.

Abaddon's forces seize two artefacts amid brutal attacks on the planets of Purgatory and Ornsworld, the Chaos Space Marines characteristically obliterating everything in their path and making off with their prizes. The Hand of Darkness and the Eye of Night as the book calls them are later implicated in Abaddon's latest megalomaniac scheme, though they are themselves never described and their exact natures are uncertain - it is however said that the Eldar "spoke of the Hand of Darkness with horror and revulsion". In this setting it is obvious to knowledgeable readers the implications of this; Eldar are frequently implicated as bearers of detailed knowledge on any topics considered 'bad news'.

War Begins

Abaddon's forces and their allies then make a dramatic entrance; warping into locations in the Gothic sector en masse and causing a massive psychic shockwave to sweep through space, which disturbs the Immaterium so greatly that travel into or out of the sector is rendered impossible. They quickly launch large scale fleet attacks on Imperial bases and shipping, crippling many of Battlefleet Gothic's capital ships while still in dock, and destroying numerous orbital stations. This spells very bad news for the Imperial Navy, already stretched thin policing shipping lanes and suppressing local pirate activity.

Events take a further turn for the worse for the Imperium when a fleet commanded by Abaddon himself strikes the naval facility orbiting the planet Rebo V - which is founded around the ancient space fortress known as Blackstone IV. The fortresses, of which six existed in the Gothic sector and were seen converted into naval facilities, were known to be extraordinarily ancient and lay largely inactive despite the best efforts of the Adeptus Mechanicus to discover their workings. Some functionality was available though, and the Navy had fitted the stations with as much of their own technology as could be powered, turning them into formidable defensive hardpoints. The Navy was confident of the Blackstones' ability to defend themselves against any fleet attack.

However, as the fleet strikes, the Blackstone's systems shut down and the battle station is rendered totally inert. The Imperial fleet defending it is routed by Abaddon's weight of numbers and Blackstone IV is captured.

The 13th Black Crusade
The 13th Black Crusade is the most recent of the incursions against the Imperium by Abbadon the despoiler, one of the few men who can claim to have controlled all nine traitor legions (apart from Horus). Every race had a reason to fight in this Back Crusade including the Tau who used the re-deployment of Imperial forces to initiate the Third Sphere Expansion. 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 Age of Apostasy
The Age of Apostasy is an era in the fictional universe of Warhammer 40,000. It's considered to be one of the bloodiest eras of the Imperium after the Horus Heresy.

It all started when the insane tyrant Goge Vandire became both Ecclesiarch and High Lord of the Administratum. He had used bribery, blackmail, coercion and murder. Vandire started the Reign of Blood and countless other wars of faith, trying to bring the Imperium under his heel. Millions died and the Age of Apostasy became the bloodiest time since the Horus Heresy.

The Reign of Blood took seven decades 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. They began to speak of hope and the people who were brutalised severely joined him. As system after system joined the movement, Vandire tried to stop them and sent a military force to crush them, but it was lost in a sudden Warp storm. By that time vast sections of the Imperium now rebelled against Vandire.'

Vandire was besieged on Terra by several Space Marine chapters including the Dark Angels, Ultramarines, Blood Angels and Space Wolves. Several Imperial guard loyalist regiments also participated. The Space marine fleet sent down a massive bombardment which caught most of the traitors in the open. Lord Vandire was killed by his generals, who are now named the Sisters of Battle, the militant arm of the Ordo Hereticus.

=The Present=

The Age of the Imperium
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 is 970-998.M41 - or the years 40,970 to 40,998 A.D. in today's notation. 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 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 awaking 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 our galaxy, beginning around 745.M41 by the Imperial Date System.

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 encircle and overwhelm 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 move 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 prevail. The Tyranids threatening Macragge are soundly beaten and retreat, while the influence of the Hive Mind falters, and finally reinforcements arrive, bringing hope for the Imperium. Imperial Navy spacecraft arrive in Ultramar, and the allies part company and renew their efforts to prevent the Tyranids regrouping. The final action against Hive Fleet Behemoth occurs in orbit of the gas giant planet of Circe, at the height of which the commander of the Imperial flagship, Admiral Rath, sacrifices 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 allow 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. Marenus 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, currently the forces of several races are fighting for control of the Medusa system