History of the Imperium

[Icarus Athrasuriel]

Well. I've been working on my first novel recently, but I hate not posting.

So, like a true fluff addict I've decided to chronicle the history of the Imperium.

Starting from the 2nd millenium A.D., I'll go right through to 999.M41, and will accompany the history with a VERY involving glossary. You have been warned.

Dark Age of Technology
circa.1,000 A.D.-25,000 A.D.

This period truly started with the Industriel Revolution in Britain, circa. 1800 A.D. though it is marked as the 2nd Millenium for ease. During this 24000 year period Mankind made it's greatest leaps forward in technology. It saw the developement of the Standard Template Construct (STC), the evolution of the Navigators, and the first use of the Warp for interstellar travel.

Age of Strife
circa.25,000 A.D.-30,000 A.D.

At some point during 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 Contruct's", or STC's, 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, 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, irridiated 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.

Control of the Sol System shifted constantly between Earth, Luna and Mars during the first half of the Age of Strife. By the 28th Millennium all traces of civilization 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 so called '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.

Eventually, an immensely powerful human leader and psyker known as the Emperor divined that the final birth of Slaanesh was nearing, as well as the effect this birth would have. He made preparations for this galaxy-changing event; he gathered military forces, began his conquest of Earth, and started the processes necessary to create his genetically tailored super-warriors, the Primarchs and then, from the Primarchs' genes, created the Space Marines.
Upon the birth of Slaanesh sometime in the early 31st millennium, the crippling warp storms were swept away (which allowed for easier galactic travel), the Eldar race was nearly annihilated, and the Emperor began to carry out his plans to reunify humankind under his rule. With the Emperor's ascension, the Age of Strife was finally over and a new age had begun. This brief age of conquest, heroism and unity would be known as the Great Crusade, and it would in turn end with the tragedy of the Horus Heresy.

The Age of Strife had a tremendous impact on human civilization. Humanity barely survived the period, and most of the knowledge of the previous golden era was lost, much of it irrevocably; in particular, the loss of the STC system is seen as a serious setback for the advancement of the Imperium. The Adeptus Mechanicus constantly searches for STC technology, and jealously guards what little it finds— in fact, it treats the STC as holy, virtually worshipping it. This focus on re-attaining and worshipping the ancient STC rather than inventing new technology, as well as the centralization of this knowledge in the hands of the Adeptus Mechanicus, has led to a stagnation of Imperial science.
Humanity as a whole became more superstitious and distrustful, something which the Imperial government goes to great lengths to encourage. In particular, the Imperium distrusts mutants, aliens and psykers; this distrust runs so deep that the Imperium has a complex secret police force, known collectively as the Inquisition, devoted to finding and destroying all aliens, daemons, mutants, unsanctioned psykers and "heretics" (anyone deemed to be straying from official Imperial doctrine) existing within the Imperium. Despite the general distrust of psykers, many critical functions of the Imperium, notably the maintenance of the Astronomican, are performed by them, so they are often rounded up by Imperial agents and forced into service. The Adeptus Ministorum (aka. the Ecclesiarchy), the official religious hierarchy of the Imperium, enforces a strict dogma including absolute devotion to the Emperor (who is treated as a god), closed-mindedness, xenophobia, and blind dedication to one's duty.
In short, the authoritarian Imperium of Man is the way it is in large part due to the great suffering endured during the Age of Strife
(NOTE:Unfinished)

[Stubber]

Not bad, all you need to do now is summerise every event in the Imperium for 28000 years...good luck to you

[Cagarner]

Wow, this is a mammoth undertaking. Truly gigantic.

by the way, you spelt industrial wrong at the start, and i would mention within the STC part, that the system also takes into account available resources that are on a planet, and compensates the design accordingly.

If you want any help, just ask...

Also, I definitely recommend wikipedia, and lexicanum

Two great sources of fluff. i would also recommend you stick close to the fluff, and do your research. Though I'm sure that the combined intelect of this community may have the answers you require.

Next time I catch you online, i've a BUNCH of fluff organised into a PDF (by someone). You'll like it I think, as it has a smaller version of what you're doing.

[Stubber]

Originally Posted by Cagarner

Also, I definitely recommend wikipedia, and lexicanum

Good call on the lexicanum site.
Seems to cover a fairly broad ammount of fluff but unfortunatly it doesn't delve too deeply.

You must now fill in the blanks Icarus.
Have fun.

[Icarus Athrasuriel]

lol, thanks.

I've trying to do this alone though, and I have a deep dislike for wiki's, as they can be edited by anyone. But of course, I'll accept any help anyone can offer. I'll put in the Age of Strife before expanding the glossary.

[Cagarner]

I have also PM'ed a link to a Fluff Bible. It has loads of information on everything.

[Leman Russ]

theres a fluff bible Cag? could you send me a link too, if its not too much trouble?

[Cagarner]

By the way, I did not produce this. I got it off a BitTorrant.

[Leman Russ]

many thanks

As a fluff nut, I endorse the bible wholly. I've checked and double checked every bit of info in it., and NEVER EVER has it yet been wrong (except in areas where the fluff is debatable, then it tries its best). Good resource to a 40K fiction writer too!

[Cagarner]

Are you talking about the one i have posted. Some of the fluff is a bit old though. And there are many sections that have been repeated, but it is a great reasource.

I think i'e a newer revised bit. Yes, some of it is old, but it is still great to draw from. And most of what it is outdated on is GLARINGLY obvious. BEen working on updating the thing actually though i've not gotten very far when compared to the mass of work.

[Corillian]

Nice, you've researched it well, can't wait untill you have done the whole history

[Dan296]

i thought GW tried to destroy the fluff bible, because it contains tons of their intellectual property, and is thus copyrighted?
great job though, there was some stuff on the age of strife i didnt know.

[Cagarner]

oh, erm... erm.... copyright.

Content removed.

You can still PM me for it though.

*thick russian accent* coapyright? Vhat iz zhis coa-pyright? *manical laugh* Een Sohvieht Russia, peepole own zee riights. (I do WWII re-enactments, and an actual russian we had in our unit said this comment. It was utterly hillarious, considerin gwe were about 15' from an MG42 and trying to explain to him how the american copyright system worked.

[Icarus Athrasuriel]

The Great Crusade
circa. 29,800 A.D.-30,000 A.D.

During the Age of Strifethe Emperor, who had spent his near-immortal life guiding and influencing mankind, was trapped on Earth, due to Warp Storms. Not content to sit on his laurels, the Emperor spent this time performing biological research on the human genetic code; specifically ones dealing with psychic powers. The result of this work was the creation of 20 highly advanced, genetically engineered superhumans known as the Primarchs. These superhumans, created from the Emperor's own genetic stock, were intended to be the next stage in human evolution.
The powers of Chaos, however, managed to infiltrate the Emperor's secret laboratory. Teleporting the unborn Primarchs away from Earth, the Emperor's plans were in disarray. With no other option, the Emperor used the stored genetic information of the lost Primarchs as a template to create the first prototype supersoldiers later known as Space Marines. Using these first Space Marines, the Emperor united the tribes of Terra under one government. This event was later known as the Unification Wars.

After nearly five millennia, the Warp storms had dissipated from Earth. With the storms gone, and extraplanetary travel was again possible, the Emperor began his plans again.

The Emperor's first obstacle was the existence of the empire of the Techpriests of Mars, who had historically been fiercely independent of Earth. Instead of an outright war, the Emperor used the threat of his Space Marines to form an alliance with the techpriests of the Adeptus Mechanicus on Mars. Despite his disdain for their reliance on religion and cybernetics, the Emperor knew that he would need Mars' factories, mechanical output and ancient technological know-how to unify humanity, and he incorporated them into the Imperium.
The Techpriests of Mars, likewise, saw the Emperor's scientific background as proof that he was the Machine God(or Omnissiah), which their religion had promised would return one day to the Red Planet and offer the way forward for humanity.

Expansion from Earth was slow, primarily due to reasons of manpower. Without the Primarchs, the time required to create a Space Marine was far longer than ideal.
After a time, the Emperor was reunited with one of his Primarchs in the Cthonian system: (Horus). Being the first Primarch (and, in some ways, his first son), Horus and the Emperor formed a truly unique bond, saving one another's' lives on many occasions. With the decreased Space Marine production time, the Great Crusade began picking up steam, with the Emperor's "Pure Human Empire" attracted entire planets to his cause.
After 30 years of successful Crusade, 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 favorite son, no matter what else.
Over time, all but two of the Primarchs were rediscovered, and given command of the Space Marine legions in which their genetic code was used as a basis. With the rediscovery of the Primarchs, Space Marine production was drastically decreased in time; a Space Marine could be made in as little as a year. This rapid creation, it should be noted, would prove disastrous: mental defects and unique eccentricities crept into the ranks.

As the Imperium grew (and there was a lesser need for a single crusading army), the Primarchs and their Emperor began to grow distant from each other. Isolated from each other, Legions began to conduct acts that would have never been tolerated in the past. For example, the Night Lordsand World Eaters Legions began to commit ever-greater atrocities, while the Word Bearersfanatical religious beliefs led to a rift between them and the Emperor.
The Imperial Army, composed entirely of normal human soldiers, provided much-needed manpower for garrison and support duties for the planets conquered by the Crusade. Freed from garrison duties, Space Marines could conquer yet more worlds in a shorter space of time. Many Marines and Guardsmen began speaking only of their loyalty to their Primarch, not their Emperor. Owing to the isolation between Legions and the Emperor, this essentially went unnoticed.

After Horus' successful campaign to destroy the Ork empire of Ullanor, the Emperor declared it the greatest victory of the Imperium to date. Horus' reward was the title of Warmaster, with it the supreme command of the Imperium's Military.
After doing so, the Emperor made it known that he was needed on Terra, where he would begin his next phase for human evolution. Horus was not informed of the Emperor's plans on Terra, and felt troubled by that. To make matters worse, some of his fellow Primarchs did not easily accept Horus's new authority, believing that the Emperor would disband or reduce their own legions to peacekeeping forces.
Horus resented his brother's feelings, which was all the powers of Chaos needed to sow the seeds of dissension into his mind. Soon, the legions rebelled. The Horus Heresy began, as did the fall of Man...

[Icarus Athrasuriel]

The Horus Heresy
circa. 30,000 A.D.

Part 1

During the Great Crusade, it became apparent that the Primarchs were far from the perfect beings they were designed to be. Although each Primarch was physically and mentally godlike, their personalities were each as flawed as those of any mortal. During their upbringing on their respective homeworlds, the Primarchs had to learn humanity from mere humans; for almost all of the Primarchs, this resulted in their harbouring all-too-human flaws (for specific examples, see each Legion's history).
Horus took over command of the Great Crusade, and took up his new duties with earnest dedication. However there was much dissension in the ranks of the Primarchs and other parties. Only a handful of the Primarchs, among them a scheming Lorgar, remained steadfast beside him during this period of dissension. Horus also disagreed with many of the Emperor's new decrees intended to shift the burden of taxation and administration onto the newly-conquered ('compliant') worlds. Even worse, Horus came to believe that he was failing his father, and was deeply wounded that the Emperor had revealed to none of the Primarchs, not even his favoured son, why he had secluded himself upon Terra. These seeds of bitterness, resentment and frustration grew, and would soon bear deadly fruit...
Meanwhile, the Emperor was on Terra organising the infrastructure for his Imperium to function. He created the Council of Terra, a body of bureaucrats and nobles that would implement and administer the new galaxy-wide tax called the Imperial Tithe and other matters of day-to-day law in the Imperium of Man.
The news of the creation of the Council of Terra and its latest bureaucratic edicts angered some of the Primarchs still further. They did not understand why they, the Emperor's greatest champions, who had spilled their blood on a thousand worlds to re-unify all the races of Man, did not have seats on this new Imperial ruling body. The brotherhood of the Primarchs was being shattered bit by bit by this growing resentment and jealousy. Old arguments and differences came to the fore. Horus became ever more distant from the Emperor, seeking only glory for himself and his Legion.
It was on the moon of the world of Davin that Horus's fate was sealed. This was the second time his Legion had been posted to this world; after the previous visit sixty years earlier the Luna Wolves had adopted the native Davinite institution of warrior lodges. Though these lodges had begun as simple fraternities of warriors, their secretive nature handed Lorgar, the Primarch of the Word Bearers Legion, and his First Chaplain Erebus, the tool they needed to manipulate Horus. Lorgar and his Word Bearers came from a world of religious fanaticism, and had long worshipped the Emperor as a living god. The Word Bearers had sought to spread this Cult of the Emperor to every world they added to the Imperium; but the Emperor hated organized religion, blaming it for much of the darkness that had plagued humanity's history. The Emperor forbade any religious worship in his empire, preferring that his subjects instead accept 'Imperial Truth'-- that reason and science alone presented the tools with which to create a better human future.
Lorgar did not suffer the Emperor's harsh reprimand well. Angered that the Emperor would not accept his devotion, Lorgar turned instead to the Ruinous Powers of the Warp - who were all too willing to accept the devotion of one of humanity's Primarchs. Before long the Word Bearers Legion had been almost entirely corrupted by the Chaos Gods, and Lorgar and his First Chaplain were tasked by the Chaos Gods with corrupting all of their fellow Space Marines--starting with the greatest of them all, the Warmaster Horus.
On Davin's moon, which had been corrupted by the forces of the Chaos God Nurgle, Horus was poisoned by a Chaos-tainted blade wielded by the Chaos-corrupted form of the Imperial Army commander the Warmaster had left behind to govern Davin sixty years before. The potent Chaos sorcery of the blade left Horus with a bleeding wound in his shoulder that his legion's apothecaries could not heal, despite the Primarch's superhuman immune system and their own advanced medical technology. Seeing his chance to further the designs of Chaos, Erebus persuaded the Sons of Horus's warrior lodge to allow a group of Davinite shamans - Chaos cultists all - to heal him.
During the rituals, Horus's spirit was transferred into the Warp. There, he bore witness to a terrible vision of the future (which his actions would bring about) - the Imperium as a repressive, violent theocracy, where the Emperor and his Primarchs (but not Horus) were worshipped as divine beings by the masses. The Chaos Gods portrayed themselves as victims of the Emperor's psychic might, and who had no interest in the material world. Horus, already having grown jealous and deeply resentful of his perceived poor treatment at the hands of the Emperor, proved all too willing to accept the Ruinous Powers' false visions. Horus decided that if anyone deserved such an accolade it was he, and not the Emperor, who deserved to be worshipped as a god. The Chaos Gods' pact with Horus was simple: "Give us the Emperor and we will give you the galaxy". He accepted the offer of the Chaos Gods to join their cause: they healed his grievous wound and also gave him access to the powers of the Warp.
Renouncing his oath to the Emperor, Horus led his Legion into worship of the myriad Chaos Gods. He then sought to turn many of his fellow Primarchs to Chaos, and succeeded with Angron of the World Eaters, Fulgrim of the Emperors Children and Mortarion of the Death Guard, who were first of many to follow, along with many regiments of the Imperial Army and several Titan Legions.
Magnus the Red, Primarch of the Thousand Sons Legion, foresaw Horus's actions through his Legion's own use of forbidden psychic sorcery. Magnus then attempted to forewarn the Emperor of the impending betrayal. However, knowing that he would have to find a means of quickly warning the Emperor, and as an act of both desperation and vindication, Magnus used sorcery to send his message to the Emperor. The message penetrated the psychic defences of the Imperial Palace on Terra, shattering all the psychic wards the Emperor had placed on the Palace - including those within his secret project in the Imperial Dungeons: the creation of a warp-gate to invade the Eldar's Webway. Refusing to believe that Horus, his most beloved and trusted son would betray him, the Emperor instead perceived the traitor to the Imperium to be Magnus and his Thousand Sons Legion. The Emperor ordered the Primarch Leman Russ to mobilize his Space WolvesLegion and take Magnus into custody; however Horus convinced Russ that Magnus was a traitor and needed to be destroyed.
Much of Horus's success arose from the thorough groundwork he had laid before the opening shots were fired at Istvaan. He had already swayed Angron and Mortarion. Lorgar, who had been responsible for the budding rebellion, was also with Horus. Three of the most loyal Legions, the Dark Angels, Blood Angelsand Ultramarines and their Primarchs, were sent on missions far from Terra and Istvaan. The Imperial Fists and White Scars were too close to Terra to be contacted without raising suspicion, though Horus believed - mistakenly - that Jaghatai Khan would ultimately take his side. Shortly before the Dropsite Massacre, Fulgrim also attempted to sway Ferrus Manus to Horus's cause, failed, and barely escaped with his life. Fulgrim promised he would deliver Manus's severed head to Horus in recompense. The Blood Angels were sent to the daemon-infested Signis Cluster and the Ultramarines to Calth, where a large Word Bearer force, under Kor Phaeron, had massed.
Of the other eventual traitors, Night Haunter was due to face disciplinary action from the Emperor; Alpharius had always been closer to Horus; and Perturabo's bitterness towards Rogal Dorn made him an easy target for corruption. The Thousand Sons had never planned to join Horus, but when betrayed by the Emperor and the trap Tzeentch had laid for the Red Sorcerer's legion led them to his side regardless.

[Icarus Athrasuriel]

Part 2

The remaining Legions - the Raven Guard, Salamanders, Iron Hands and Space Wolves- remained staunchly loyal to the Emperor, though all but the Wolves would pay dearly for it in the battles to come. Beyond the Legions, Horus had already swayed Adept Regulus with promises of the STCs recovered during the war with the Technocratic Brotherhood, delivering Mechanicus support to the Warmaster's forces.
The first sign that Horus and his Legion had turned to Chaos was made evident when Horus virus bombed the rebel world of Istvaan III. The Planetary Governor of Istvaan III had declared his independence from the Imperium, and the Council of Terra charged Horus with the retaking of that world. This order merely furthered Horus's plans. Although the four Legions under his direct command had turned Traitor, there were still some Loyalist elements within the Sons of Horus, World Eaters, and Death Guard; many of these were Terran Space Marines who had been recruited before being reunited with their Primarchs. Horus, under the guise of his orders, amassed his troops in the Istvaan System.
Horus had a plan by which he would destroy all Loyalist elements of the Legions at his command. After a lengthy bombardment, Horus despatched all Loyalist Marines down to the planet, with the pretense of bringing it back into the Imperium. At the moment of victory, however, these Marines were betrayed when virus bombs began to rain down on the planet. However, some Marines loyal to the Emperor had remained onboard their ships, and as Istvaan III died, these soldiers fought desperately to warn their brethren on the surface. Their sacrifice saved many Space Marines, as they were able to take shelter before the virus bombs struck. The population of Istvaan III received no such protection. Sixteen billion people died almost immediately. The psychic shock of so many simultaneous deaths shrieked through the Warp. A contingent of Loyalists led by Captain Garro of the Death Guard escaped the fleet orbiting Istvaan III aboard the damaged vessel called Eisenstein, and fled to Terra to warn the Emperor.
Angron, realising that the virus bombs had not been fully effective against the Loyalist Marines, flew into a rage and hurled himself at the planet with 50 companies of Marines. Horus was furious at Angron for delaying his plans, yet reluctantly reinforced him with troops from the Sons of Horus, the Death Guard, and the Emperor's Children. On Istvaan III, the remaining Loyalists, under the command of Saul Tarvitz, fought bravely against their own traitorous battle-brothers. But their cause was doomed. Soon only a few hundred of them remained until, finally, Horus grew unable to tolerate the delay and forced Angron to withdraw his forces, and ordered a systematic orbital bombardment that killed Istvaan III's last brave survivors.

The seventy Loyalists led by Captain Garro commandeered the Imperial frigate Eisenstein and, evading the forces of Horus, were able to escape from the Istvaan System into the Warp. The Eisenstein was badly damaged during its escape from Istvaan III; all its astropaths were dead, and its lone Navigator was mortally wounded. However, Garro managed to attract the attention of passing Loyalist ships by setting the vessel's Warp engines to self-destruct and ejecting them from the ship. Rogal Dorn's Imperial Fists Legion had been becalmed in the Warp with its fleet for some time, and his Navigators sensed the detonation of the Eisenstein's Warp drives. Making an immediate course for the location of the ship's beacon, Dorn met with Garro, who explained to him all that had happened with the Traitor Legions.
The Eisenstein was able to reach Terra, allowing the loyal Marines to report the extent of the atrocities that had occurred in the Istvaan System. It was said in later millennia that without this warning, the Imperium would have faced even greater difficulties responding to Horus's final moves.
The fate of these seventy Marines is ultimately unknown. Some believe they continued to fight for the Emperor until death claimed them, while others maintain that they were treated as if they were their traitorous brethren, either imprisoned and left to rot, or executed. Others believe that Captain Garro, shocked by the terrible betrayal, became an Apothecary, vowing never to kill again.
Yet there is another story concerning their fate. Malcador the Sigilite had presented eight of the survivors to the Emperor before his departure. These men were gifted psykers, came from the ranks of the Legions that had turned Traitor, and yet maintained both an unbreakable faith in the Emperor and talent for resisting the temptations of Chaos. Many believe these men formed the nucleus of the elite Space Marine Chapter known as the Grey Knights.

[Icarus Athrasuriel]

Part 3

In response to Horus's betrayal, Rogal Dorn ordered seven Space Marine Legions to Horus's base on the world of Isstvan V to challenge the Warmaster. These Legions were the Iron Hands, Raven Guard, Salamanders, Iron Warriors, Night Lords, Alpha Legion and Word Bearers. Of these, the Night Lords, Alpha Legion, Iron Warriors and Word Bearers had all turned to Chaos.
The three Loyalist Legions, the Iron Hands, Salamanders and Raven Guard, were deployed in the first wave, and attacked the Traitor Marines' forces. As they gained a foothold on the planet, at a heavy cost, Ferrus Manus's obsession with confronting Fulgrim came to the fore and he abandoned his post as Supreme Commander. As the two dueled, Horus committed his hidden reserves, swamping the beleaguered attackers. They fell back towards the drop zone the other four Legions had established, only to be fired on by their 'allies'.
Each Loyalist Legion was almost destroyed in the resulting bloodbath, recorded in Imperial history as the Drop Site Massacre. Ferrus Manus was slain by Fulgrim as all around him his veterans were massacred. Some believe Alpharius, Primarch of the Alpha Legion, planned the operation jointly with Horus. Of the three Legions loyal to the Emperor on Istvaan V, only a handful of survivors escaped, including a critically wounded Primarch Corax of the Raven Guard. The Drop Site Massacre is also the last known place where the Primarch Vulkan of the Salamanders Legion was seen.
(Note: Vulkan was heard from after the end of the Heresy, as, like Russ and Dorn, he is recorded as having objected to the Second Founding. This event is supported by Index Astartes: Black Templars and the Black Templar Codex. The fate of Vulkan is unknown, so some assume the piece concerning the discussion about the Codex Astartes was a mistake in the lore and Vulkan is dead. However, since Index Astartes: Salamanders doesn't mention more, Vulkan's fate remains unknown.)
After the Drop Site Massacre, it became clear that eight of the eighteen Legions had turned to Chaos. Horus openly declared that he would no longer follow the Emperor, believing him to be undeserving of the battles fought in his name, and took leadership of the Traitor Legions, supported by elements of the Imperial Army, a large portion of the Adeptus Mechanicus, and the daemon-spawn of Chaos. Their aim soon became clear: Terra, the heart of the Imperium.