Index Astartes – Iron Warriors : Keepers of the Cages

Sons of the Emperor's own Praetorian, the Iron Warriors are the eternal defenders of the Imperium. From hundreds of mighty fortresses, they watch over their grandsire's kingdom, and ensure that the traitors of the mythical age do not ever return. They are the guardians of the faithful and the gaolers of the damned, masters of the arts of siegecraft and fortification. Following Perturabo's teachings, they do not seek glory in war, only maximum efficiency, using cold logic and tactical previsions over feats of heroism and valor in battle. But in their heart and flesh, despite their dedication to the cause of the Imperium, burns a bitterness that poisons their soul, and they must ever be vigilant to not fall to the deceptions of the Ruinous Powers.

Origins

When the Dark Gods stole the Primarchs from the Emperor, they dispersed them across the length and breadth of the galaxy. The sons of Mankind's master would rise to glory or infamy according to their own nature and that of the world they found themselves on, knowing that they were different from all around them. But most of them would not understand what they really were until the Emperor found them again. Horus would learn his nature very soon, when he met his father on Cthonia while still a child, and Magnus of Prospero knew it from his birth, his intellect already beyond that of most mortal.

As for the fourth Primarch, the most detail accounting of his life is to be found in The Lord of Iron, a biography redacted by the remembrancer Solomon Voss, who listened to the Primarch himself tell the tale in the days following the Heresy. According to the book, Perturabo awoke in a great crater at the bottom of a cliff, on a world called Olympia by its inhabitants. Though he did not know what he was, he knew his name, the one that the Emperor had intended to give to him before he was taken away : Perturabo. This was the first sign of the Primarch's extraordinary intellect, but far, far from the last. After climbing the several kilometers-high cliff, Perturabo was found by soldiers of the city-state of Lochos, and brought before their lord and master.

Dammekos, the Tyrant of Lochos, was to be Perturabo's foster father. What he saw when he first laid eyes upon the Primarch, none can say for certain. But it convinced him to take this strange youth under his aegis, and raise him as he would have his own flesh and blood. Perturabo's mind was ever-hungry for more knowledge, and he learned all that his tutors could taught him in the span of a few years, while proving his value as a tactician at many of his father's war councils against his many rivals. His intellect was a razor-edged blade that could find the weak spots into any fortification, and with his input to his foster father's tactics, the stalemate that had held Olympia's city-states in its grip for centuries began to crumble. Perturabo himself was given command of an army in several instances, and he led them to victory with a tactical insight that was matched only by his ruthlessness. It is said that he used maximum brutality to defeat his enemy, so that the others would be cowed into submission without fighting and causing unnecessary loss of life, but others say that it was only after these first battles that, witnessing the horrors of war for the first time, Perturabo swore to never find any pleasure in it.

With the implacable hand of his foster son supporting him, Dammekos conquered city after city, building an empire on the montainous world. But before he could achieve his ambition – a united planet under his rule – he died in what is said to be an accident, but what many suspect was engineered by Perturabo himself. Regardless of the truth of these accusations, it is known that the one who would come to be called the Lord of Iron had grown more and more distasteful of his father's attitude over the years. Dammekos had lived up to his epithet of 'Tyrant', and the inhabitants of the cities his foster son helped him conquer were reduced to little more than slaves. This was not what Perturabo had envisioned when he had helped Dammekos; the young man had wanted to help put an end to the endless feuds between the planet's lords, not help establish a despot whose rule would be even worse. Still, Dammekos was not only his foster father, he was the Primarch's liege, and Perturabo held his given word in high value even in these early days. It is thus unlikely he had anything to do with the Tyrant's death.

Perturabo was Dammekos' rightful heir, but he had many rivals amongst his foster father's court. While none of them were brave or foolish enough to challenge him for Lochos' rulership, they did everything they could to diminish his influence and force him to negotiate with them, allowing them to gain more power over the domain he had inherited. For a time, Perturabo tolerated their petty games of intrigues and deceit, only punishing those against whom he had definite proof of treachery. But after ten years of such plots, with his dream still unachieved because of the greed and envy of lesser men and women, his patience finally came to an end.

The corpses of noblemen were spread all around the banquet room, butchered almost beyond recognition. They had all come here this evening at the behest of Perturabo, invited to speak of Lochos' future, thinking that the brute sitting upon the Tyrant's throne had finally understood he could not rule the city-state without them. But they had been wrong.

The moment the gates of the room had closed, Perturabo had risen from his throne and hold up his mace. The fire of his rage, which had been hidden for so long, had been unleashed, and the men and women who had hindered the Primarch's vision out of petty ambition had been petrified as they witnessed his full might for the first time. They had never seen him in battle – such base affairs were beneath those of their station – and they had thought the tales of his prowess to be mere exaggeration and propaganda spread by the weak, crude minds of the soldiery. But they had been wrong. If anything, the stories did not do justice to the Lord of Iron, for he had never before let himself exert his full strength against mere mortals.

It had been a slaughter. When the servants of Perturabo, sworn to never speak of what had occurred this night, opened the doors at dawn, they found their lord standing amidst the carnage, looking at what he had done with wide eyes. His weapon was abandoned on the ground, covered in the blood of traitors and liars. Yet despite the fact that their master was now free to do with Lochos as he pleased, they saw only sorrow, regret and utter horror in his eyes.

When his temper went down, Perturabo was horrified by what he had done. Though these men had deserved their fate and brought it upon their heads by their own actions, the Primarch had still broken the laws he had sworn to uphold. All rulers of Olympia had done the same throughout the ages, but Perturabo wanted to be different. It was then that he swore to never do the same mistake again, to always follow the rule of law and reason, and to never let his rage take control of him again. After speaking that oath, he returned to his task with renewed determination.

In a mere few decades, Perturabo united all of Olympia under his banner. He purged his kingdom of the fear and bitterness that held the other domains in their cold grip, building a haven of peace and freedom, protected by the revolutionary weapon designs he had created and the armies he had raised. While he stood at the top of his new society, he did not rule as a tyrant as all rulers had since the coming of the Age of Strife. Instead, he let the mortals around him govern themselves, only providing them direction and advice. As word of his kingdom's prosperity and his ideals of democracy spread, entire populations rose to overthrow their own overlords, joining with his growing nation. More and more city-states did so over the years, until at least, all of Olympia was united, at peace, under the eyes of the Lord of Iron.

It was almost a century after Perturabo's arrival on Olympia that the Emperor of Mankind found him. He descended on the capital of the world with His Custodes, walking the perfect streets of a city built in accordance to Perturabo's ideal proportions and architecture. Perturabo waited for his father on his house's doorstep, and the Emperor's escorts were surprised to find their liege's son not in a lavish, grand palace, nor in one of the titanic fortresses that towered above the peaks surrounding the cities. Instead, they found Perturabo at the door of a simple home, where he had spent the last decade perusing ancient writings and working on his designs, his task on Olympia done.

Perturabo looked at his father, unease in his eyes. He had concealed it so far, while the Emperor had told him of the newborn Imperium, of His desire to conquer the galaxy in Mankind's name. It was a glorious vision, of that there was no question. But Perturabo cared nothing for glory. And so, now he let his doubts show on his face. He knew the man in front of him – if He could be called a man at all – would see them. How He would react, however, the Iron Lord did not know. It would reveal much of his father's nature, of that he was certain. Would He deny Perturabo's ideals and philosophy, and force him into service as an agent of conquest or destruction ? Or would He accept his dreams, and share them ?

The Emperor smiled, and for a moment Perturabo faced not the warlord that had come from the skies with a hundred battleships, but the old, wise and tired man that lived behind that mask.

'You really are my son, Perturabo,' the Emperor said in the voice of a father whose son is making him proud. Then the Master of Mankind told His son of His goal for humanity, and the Lord of Iron listened.

The contents of the exchange between Perturabo and the Emperor remain unknown to all safe the two, but it did put the Lord of Iron's mind at ease. He left Olympia in the hands of the mortal rulers he had raised and taught, and journeyed to Terra. It is said that while the people of the world rejoiced that their benefactor had finally found his roots, and welcomed their integration into the Imperium with open arms, they wept at Perturabo's departure.

On Terra, Perturabo met his brother Magnus the Red. The two immediately became close friends, united by their shared interest for the lore of Mankind's past. Together, they explored the ruins of Old Earth, seeking to uncover more of its secrets, and spent many hours together, discussing the philosophies of ages long past and the secrets of the universe. In the decades to follow, the friendship between the two Primarchs would be echoed between their Legions, and they would fight many campaigns side by side, especially as the Thousand Sons grew more and more isolated in the Imperium.

Magnus paused in his explanation of the political upheavals of the Firenzi's era. He could feel that his brother wasn't really listening. There was a shadow in his usually clear as crystal thoughts, a doubt that was poisoning him. The Cyclops felt that Perturabo wanted to tell him something, yet hesitated in doing so. He was ... not afraid, no, not that – Magnus doubted anything in the galaxy could scare his stalwart brother – but ...

'Magnus,' Perturabo began, breaking his brother's thoughts. 'I ... I need your advice on something. Something regarding the Warp, I think.'

The Crimson King listened to the Lord of Iron's tale. He learned of something he had never suspected, and would curse himself for a fool many times for not realizing : that Perturabo was not psychically ungifted – as much as any Primarch could be called such a thing. His brother could see, had always seen if his tale was true, the Warp Storm near the center of the galaxy. It had always been here in the night sky, a blight upon reality than no one else seemed to be able to notice.

Magnus couldn't begin to imagine how Perturabo must have felt, seeing something no one else could see. At least in Magnus' own case, he knew why he could see beyond his teachers' reach. Now the source of his brother's unease was clear : he was worried that what he saw meant he was corrupted in some way, touched by the Warp when they had been taken from their father.

'Do not worry, brother,' said the Cyclops when Perturabo was finished. 'Let me explain to you ...'

The Great Crusade

After his sojourn on Terra, Perturabo took command of the Iron Warriors. The Legion had been, up to that point, used as a sledgehammer by the commanders of the Great Crusade, a weapon of little subtlety but devastating power. Their mastery of siegecraft and dedication to their duty had made them the most favored Legion to call upon when the Expeditionary Fleets were faced with seemingly impregnable fortresses. There was little honor in such campaigns, and unrest and doubt were beginning to spread amongst the Fourth Legion by the time their Primarch was found.

All of that changed, however, when Perturabo took command of the Legion that had been made in his image. He taught them his philosophy and approach to war, and renamed them the Iron Warriors. The Fourth Legion then returned to the Great Crusade with renewed determination, ready to do its duty no matter the cost or whether or not their efforts were acknowledged. Their father's approval was enough for them.

'There is no glory in war, my sons. War is unequivocal, uncaring, unforgiving and blind. Let your cousins revel in their victories if they so wish. It is a lie, but it makes the hell of battle tolerable. But we are not so weak as to need to cover our eyes from the truth : war is an ugly, terrible thing. But it is necessary. If the Emperor's dream is to be achieved, my sons, then we will need to be soldiers unlike any the galaxy has ever seen. I have watched you, and I have seen your worth. You fight not for glory or for honor, but because you are ordered to do so, because it is your duty. You see war not as an opportunity for heroism, but as a mathematical equation that needs to be solved as quickly and effortlessly as possible. You are already the weapons Mankind needs you to be, and you shall be forevermore. You are the Iron Warriors !'

Extract from Perturabo's speech upon his raising as commander of the Fourth Legion.

The Iron Warriors were separated across the Great Crusade once more, with the bulk of the Legion remaining under Perturabo's direct command while the rest joined with other Expeditionary Fleets. During the next century, they earned much honor by turning campaigns that had been locked in stalemates for years – sometimes decades – into victories in a matter of month. The concern they showed for the mortals who fought at their side by being careful not to waster their lives became renowned across the Fleets. Many of the most sensible commanders of the Imperial Army would strive to be assigned to an Iron Warriors' command, for while the sons of Perturabo did not pursue glory, the lives of those fighting under them were never spent in vain. That is not to say they hesitated to take risks : during the war for Meratar Cluster, Perturabo himself ordered tens of thousands of men to their deaths in order to bring down the techno-overlords of the region, the self-proclaimed Black Judges. This earned him the favor of the Mechanicum, but it is said that the Lord of Iron spent many a night brooding over the sacrifices he had caused. Still, the war machines he was able to demand from the Cult of Mars in return for this victory increased his Legion's military might greatly. The creations of the Legion Cybernetica would fight alongside the Iron Warriors in all of their campaigns from this point, and the Techmarines of the Fourth Legion would learn much from the Priests of the Machine-God. The investment of the Meratar's crusade would ultimately prove valuable beyond measure, but it would do little to appease Perturabo's conscience.

Apart from his friendship with Magnus, Perturabo generally stayed away from his brothers. He couldn't bring himself to share in the joy they took in battle, and refused to lie to those who shared his blood by pretending he did. This caused him to develop a reputation as a dark, brooding man, who didn't care for the brotherhood of soldiers and to whom only the cold mathematics of war mattered. Not all Primarchs shared this opinion, of course : Horus himself acknowledged Perturabo's talents, and his disinterest for the honors of battle always made the First Primarch smile, as it reminded him of his own prideful streak. A few campaigns alongside the Dark Angels made the Lord of Iron admire Lion El'Jonson's tactical insight, though he was a bit unnerved by the callousness his brother could display at times. Perturabo and Fulgrim were never close, though they had a grudging respect for each other's martial skills – the Lord of Iron saw the Phoenician as too focused on glory, while the Primarch of the Third Legion thought his brother was needlessly consumed by remorse by refusing to enjoy what he was born to do.

While one could be forgiven for thinking the Primarch of the Fourth Legion should have felt close to the lord of the Tenth, given their common interest for technology, Ferrus Manus and Perturabo disagreed vehemently on their approach in such matters. Perturabo saw every single one of his designs as a way to serve Mankind, while Ferrus believed the Machine to be inherently superior to the weak flesh of man, and destined to replace it. The Tenth Primarch's philosophy was closer to that of the Mechanicum, and the full, cruel irony of that would not be lost in the dark days to come.

But it was with Rogal Dorn of the Imperial Fists that Perturabo's relationship was the most strained. The master of the Seventh Legion was as much an expert of building and destroying fortifications as Perturabo, but what began as mere rivalry between the two of them quickly turned into bitter disgust for each other's methods of war. Dorn saw Perturabo's calculations and plans as cowardly, while Perturabo believed Dorn's prefered method of full-front assault to be needlessly wasteful in the lives of his Legionaries. Besides, Dorn's own arrogance and desire to be recognized and glorified by the Imperium was irked by Perturabo's own attitude – instead of taking it as a lesson like Horus, he took it as a personal affront. After the two Primarchs nearly fought each other in their first joint campaign (the events of which have been lost to the ages), the two Legions never went to war side by side again.

Perturabo stared at the corpse of his son with fury in his heart and murder in his eyes. On the opposite side of the slab, Rogal looked at him with incomprehension in his gaze.

'Why ?' grunted Perturabo. 'Why did your First Captain kill my son ?'

Rogal shrugged.

'It was a matter of honor, he told me. I trust Sigismund on these matters. Besides, it was a duel. Your son had his chance to refuse.'

'He insulted him. He provoked him ! Don't you dare absolve your precious Captain of blame, Rogal ! I want him punished for this !'

'Then you will be disappointed,' answered Rogal with a voice as cold as the snow of his homeworld. 'I do not think Sigismund was wrong in this. Now, if you will excuse me ...'

The Primarch of the Imperial Fists turned and walked toward the exit of the Ironblood's Apothecarion. Before he left, Perturabo hailed him one last time :

'This isn't over, Rogal.'

'Oh, I think it is, brother'. Then the lord of the Seventh Legion left his brother with the stasis-preserved corpse of Warsmith Berrossus, killed in duel by Sigismund, Captain of the Imperial Fists' First Company.

With its casualty rates diminishing as the thirst for glory was abandoned, the Fourth Legion grew in number, to the point it was second only to that of Guilliman himself (until Corvus Corax was found, and the Raven Guard embraced its dark Primarch's vision). But despite that strength, the Iron Warriors were unable to field as many warriors as the other Legions on a single campaign, for they were spread too thinly. In regions of the Imperium that were still unstable, the sons of Perturabo were assigned to garrison duty, protecting the supply lines of the rest of the Great Crusade. Entire Grand Battalions were stationed to the borders of the Ork Empire of Urlakk Urg, to prevent the beast's Waaagh to spread to the rest of the Imperium. After one too many reports from his sons telling him of the casualties the Orks had inflicted upon them, Perturabo resolved to call his brother Horus for help. While he was loath to admit to any weakness, the Lord of Iron knew he couldn't defeat Urlakk Urg without all but destroying his Legion in a terrible, grinding war that would take decades. The situation simply wasn't one that played to the strengths of the Iron Warriors. Horus answered his brother's call, persuading the Emperor to accompany him in what would be the last battle the Master of Mankind would fight alongside the Legions. The White Scars, under the leadership of their Primarch Jaghatai Khan, were also called upon to help purge the galaxy from the tumor of Urg's empire.

Thus began the Ullanor Crusade. While the Iron Warriors relentlessly assaulted Ork positions, drawing the bulk of the Waaaagh to them, and the White Scars sowed havoc and destruction amidst the xenos' ranks with lightning raids, the Emperor and Horus struck at Urlakk Urg himself, slaying the beast and breaking his troops' morale. After the victory, the Emperor ordered a great triumph to be held at the site of the final battle, and the Fourth Legion received much of the honor – though the lion's share, as always, went to the newly renamed Sons of Horus. When the First Primarch received the title of Warmaster, Perturabo rejoiced for his brother's ascension, seeing Horus as the one who could best lead the Great Crusade in the Emperor's absence – though the Lord of Iron did harbor concern about his father's return to Terra, he trusted in Him and Magnus. In the decades that followed, Perturabo was one of Horus' most fervent supporters, following his command without resistance and bringing dozens of systems into the Imperium.

Praetorian of the Emperor

Years after the Triumph of Ullanor, the Emperor called for a gathering of His sons once more. The unrest concerning the use of psychic powers amongst the Legions had only grown since Horus had been appointed as Warmaster, despite the efforts of the First Primarch to bring his brothers to accept the Librarium in their forces. Perturabo was tasked by the Emperor to build the amphitheater of Nikea, where the Conclave would gather and the Master of Mankind would render his judgement. Though Perturabo was filled with concern over what the final decision of his father would be, he followed his instructions, creating a place worthy of hosting such a tremendous decision.

During the debate, Perturabo spoke in favor of the Librarians. He told his brothers that their enemies would not stop to use the Warp as a weapon if they choose not to. Beyond his friendship to Magnus, whose silence he couldn't explain, there was a core of cold, brutal logic to his argument. For the Lord of Iron, to not use a weapon, especially one as useful as the Librarians, was not just foolish : it was an insult to all those whose death could have been avoided had one of the psychically gifted be there.

To the unmasked relief of the Lord of Iron, the Emperor approved his opinion, and declared that all Legions would now make use of the Librarium amongst their ranks. Perturabo had already established one in his Legion, and to see his choice – one that had brought him even more scorn from some of his brothers as he had endured before – vindicated was immensely wrath of Russ at that announcement cast a shadow over Perturabo's joy, but the next words of his father stupefied him.

It was the will of the Emperor that Perturabo and his sons return with Him to Terra, where they would fortify the Imperial Palace and the Sol system as a whole. Perturabo, who had never sought the honors bestowed upon his brothers, was to be the Emperor's own Praetorian. Magnus was delighted to be thus reunited with his brother, but Rogal Dorn was far from feeling the same. The lord of the Imperial Fists believed himself to be far more worthy of such an honor than Perturabo, and publicly challenged the Emperor's decision. He was rebuked, and his Legion shamed when the Master of Mankind told him that he had proved his inaptitude to the task by his very conduct this day. Seething with rage, Dorn left, and began to lead his Legion to the most murderous and hard-fought battle-zones of the Great Crusade. Ostensibly, this was in order to atone for his misconduct, but even back then rumors spread of the Imperial Fists' growing ruthlessness and cruelty.

Despite feeling unworthy of the honor that his father had granted him, Perturabo resolved to do his very best in his new task. He called back full half of his Legion, leaving the rest to man the garrison that had yet to receive human troops to replace them and finish the campaigns the Iron Warriors were already engaged into. With tens of thousands of his sons, he then set himself to work in the Sol system. In order to avoid marring the supreme beauty of the Imperial Palace, he externalized the defences, building a chain of void stations and asteroid-fortresses at the Mendelev belt of the Sol system. Not a single ship could enter or leave Terra's surroundings without being detected. Behind that first circle of defence, the Praetorian built hundred of hidden garrisons and artillery posts. The cost of this work in manpower, resources and technology is beyond anything we in this forty-first millenium could possibly imagine, but it proved worth it a thousand times when the unthinkable happened.

Time passed, while unknown to the Imperium the seeds of Heresy were being sown. Then, news arrived to Terra : Olympia was under attack.

The Olympian War

The homeworld of the Fourth Legion, which had given it tens of thousands of its youths as Legionaries, was surrounded by a mighty fleet of the xenos breed known as the Hrud. The aliens, who had been believed wiped from the galaxy in a previous campaign of the Iron Warriors, had come back from the very brink of oblivion to take their revenge. The Astra Telepathica's reports spoke of hundred of scavenged Imperial ships, thought lost to the Warp and used by the xenos to lay siege to Olympia.

The Hrud

Also called the 'Temporaferrox', the Hrud are believed to be one of the oldest species of the galaxy, along with the Eldars and the Orks themselves. They are spread across the stars like a plague, and despite repeated attempts to wipe them out, they always seem to reappear.

The Hrud are humanoid in form, with an exoskeleton allowing them to twist their bodies at will. They possess the ability to distort the fabric of time and space around them, though whether this is a psychic power or some natural skill remains unknown. For centuries, agents of the Ordo Xenos have tried to capture one of the Hrud alive – for dissection, the most favored avenue of study of the Imperium's xenobiologists, is impossible to perform on these creatures who dissolve upon death. But so far, none have succeeded.

The Imperium first encountered the Hrud during the Great Crusade. The Iron Warriors led a campaign of extermination against them, and endured great losses in this war. The Hrud's unique physiology made them the bane of the Fourth Legion's tactics, which relied heavily on technology that broke down in the xenos' presence. Perturabo himself joined the fight, adding the forces of his own Expedionary Fleet to those already present, and broke the aliens' advance before seemingly exterminating them. That belief would hold until the moment they attacked Olympia, at the onset of the Roboutian Heresy.

After briefly conferring with his father, Perturabo was allowed to lead a small elite force of his Legion to defend his homeworld. With ten thousand Astartes, millions of soldiers of the Imperial Army and a hundred ships, the Primarch of the Iron Warriors traveled through the Warp at full speed. During the journey, the Sea of Souls began to rise in a storm, and by the time the fleet arrived at Olympia, a full third of it had been lost to the tides of the Warp.

Perturabo found his world still holding against the xenos, though its once pristine cities had been razed by orbital bombardment. The orbital defences he had installed had been crushed, not thanks to any skill from the xenos, but with sheer numbers. The people of Olympia were waging a desperate war in their underground bunkers and ruined fortresses, fighting against the Hrud, who were themselves nocturnal, subterranean creatures, and thus best adapted to such fighting. The children of Perturabo's pupils were fighting well, with the last surviving Legionaries of the Olympian garrison leading them.

The relief fleet struck the Hrud like a hammerblow. Perturabo himself led the boarding actions, crippling the vessels with relative ease – most of the xenos forces had already made planetfall, leaving only a token force to protect their ships. The Iron Warriors retook the orbit of their homeworld with little effort, and then began their counter-assault on the aliens.

In an earlier age, the ship had born the name Principio.

Perturabo was standing on the command deck, reading the information flowing on the data-pad he was holding while distributing his orders to his officers concerning the planetfall. His mind could easily do the two things at the same time. He needed to know how the Hrud had managed to acquire such a fleet. Even if the xenos had somehow managed to escape his purge decades ago in such numbers – something he still found difficult to believe – there was something strange in the composition of the fleet. The Hrud were scavengers, gathering ships from all space-sailing races in the galaxy to compensate for their apparent inability to build their own. And yet, this fleet ... It was made almost entirely of Imperial ships. There was something wrong ...

He froze as he reached the point of the Principio's manifest he had been looking for : the last entry, before the ship had been lost to the Warp and his crew destroyed by the things dwelling in the Sea of Souls.

It read : 'Last day aboard. Hrud will arrive tomorrow. Hope the Principio fights well against the Olympian bastards.'

Once the battle in orbit was won, Perturabo and his men descended upon Olympia like the gods of the world's myths. They struck at the xenos with merciless fury, tearing through their ranks to join with the survivors. The Primarch had brought with him the best warriors of his Legion, veterans of a hundred campaigns who had all fought in the first wars against the Hrud. They fought with the fury only those who fight for their homeworld can display, and crushed the xenos' main force in a single battle.

The fight took place in the ruins of fair Lochos, the city that had taken the brunt of the xenos' spiteful destruction due to its importance to Perturabo. This time, the Hrud didn't face the terrified mortal population of the planet, or its hopelessly outnumbered defenders. They faced the wrath of a Primarch and his chosen sons. The Iron Warriors matched the strange abilities of the Hrud with their own weapons, using technologies rediscovered by the Lord of Iron on forgotten worlds, or entirely innovative machines of his own design. These were tools of war whose use was frowned upon by the Imperium, but Perturabo was the Praetorian of the Emperor Himself, and he believed that the situation called for drastic mesures indeed. By using ancient secrets that were capable of rending down the very fabric of time and space, Perturabo took away the Hrud's greatest advantage, though the consequences for Olympia remain uncertain to this day. However, even after their main army was annihilated, thousands upon thousands of Hrud remained, scattered across the surface and caverns of Olympia. Under Perturabo's command, the Iron Warriors began the purge of their homeworld, building great pyres upon which the tainted flesh of the aliens was set to burn.

The cleansing of Olympia took months, during which Perturabo himself was the target of many attacks from Hrud infiltrators. The xenos knew of his presence, and remembered well who it was who had led the campaign of extermination directed against them. But, protected by his Iron Circle – a cadre of robotic bodyguards he had crafted himself, which existence raised much concern in the more puritan factions of the Mechanicum – the Primarch of the Fourth Legion survived all of them and captured more than one of his would-be murderers. From them, he heard many disturbing things – the xenos claimed that the Lord of Iron had been betrayed by his own blood, that his kin had helped the aliens survive and prosper after his purge. They claimed that the ships with which they had launched their vengeful assault on Olympia had been given to them, not stolen or scavenged.

Perturabo believed none of it, of course. He had the prisoners executed when it became clear they would yield no true, valuable information. Whether or not he already had doubts then, before they were confirmed in the most horrible of ways, none but him know.

The Tides of Heresy

Upon his return from Olympia, Perturabo learned the truth of the Roboutian Heresy. What he had apparently dismissed as the plots of mad xenos in the forlorn hope of shaking his trust in his brothers was revealed to be the absolute, ignoble reality. Legends has it that when he heard the news, his rage was such that it shook the Imperial Palace on its very foundations. Such claims can probably be dismissed as exaggeration, yet one must not forget that the Primarchs were beings far beyond our current understanding of the genetic craftwork that created them.

Horus calmed his brother's wrath, and asked him to focus his energy on fortifying Terra while the Warmaster marshalled the forces of the Imperium to bring the Traitor Legions to heel. With the Emperor and Magnus gone in the depths of the Palace, fighting a war of their own, it fell to the Lord of Iron to organize the defences in the case the seven Legions sent to Issvan somehow failed in their mission. First, they had to free Mars from the traitors who had pledged their allegiance to Guilliman. Perturabo sent one of his Triarchs, the officers of his Legion who advised him personally, to take back the Red Planet from the hands of the heretics. With thirty thousand Iron Warriors under his command, Barban Falk vowed not to return to Terra until the rebels were put down.

The Martian Wars

Precious little is known to the Inquisition of what happened on the soil of sacred Mars during the dark times of the Roboutian Heresy. The archives of the Heresy have suffered much in ten thousand years, but it seems there was precious little about the so-called 'Schism of Mars' in them to begin with. Due to the secretive nature of the Cult of Mars and the madness that took place, that is hardly surprising, but entire teams of the Ordo Hereticus have gathered what is believed to be a reliable accounting of the Red Planet's darkest days.

It is believed that the Arch-Traitor spent many decades subverting lords and potentates of the Mechanicum to his cause, promising them to share the many secrets he had found during his fall to Chaos, and to release them from the restraints the Emperor, in His wisdom, had placed upon the Imperium's technology and what avenues of research were forbidden.

When word came to the Sol system that Guilliman and three of his brothers had turned against the Emperor, alongside with their Legions, the Red Planet erupted in a civil war that would be mirrored across all the hundred forge-worlds and outposts of the Cult of Mars in the galaxy. Kelbor-Hal, the Fabricator-General of Mars, was trapped in his forge of Olympus Mons by legions of traitor skitarii and almost all the Titans of Legio Tempestus. He held his ground, using his own considerable armies and wisdom, but was effectively cut from the rest of the Mechanicum.

With the only man capable of coordinating the different loyalist forces on Mars isolated, the rest of the Red Planet descended into wild, savage anarchy. Countless treasures and lore that had endured the Age of Strife against all odds were lost to the fire of betrayal. Even more was destroyed when the traitors, seeking to reclaim the knowledge that they had possessed during the Dark Age of Technology, opened the infamous Vaults of Moravec, releasing an host of horrors and viruses that spread across the surface of the world. The corruption of Chaos twisted entire forge-cities into nightmarish hells that the loyalists had to purge with nuclear fire, destroying what little progress had been made in terraforming Mars again since the Unification.

When Barban Falk returned to Terra, with less than three hundred Astartes accompanying him, he reported to his Primarch, telling that his mission was done. Mars' great forge-cities were all either in loyalist hands or destroyed, and the Lords of the Red Planet had the forces required to defend themselves from the remnants of the traitor forces. Kelbor-Hal and Olympus Mons had been rescued from the traitors' siege, and the Fabricator-General would soon be able to begin provide the Praetorian with the supplies he required. The exact details of what Falk and his men saw and did on Mars is known to no one, for they never spoke of it.

'I am Barban Falk no more, father. That man died in the Noctis Labyrinthus. I am the Warsmith.'

Months later, Mortarion and the ragged survivors of Isstvan V returned from the Atrocity, and the full scope of Guilliman's treachery was revealed. No longer allowing his rage to surface, Perturabo focused on the fortification of the Imperial Palace. While before he had been careful not to maim the beauty of the Emperor's domain, he was now no longer concerning himself with such matters. He tore down frescos that had taken decades to create, and dismantled works of art such as Mankind had never seen before to place batteries and forts in their place. To this day, the reputation of the Iron Warriors as artless barbarians is still well engrained in the Terrans' minds.

The Fortress Worlds

As the galaxy burned in the flames of ultimate heresy, the Iron Warriors remained steadfast in the face of their kindred's betrayal. While most of their number had returned to Terra, thousands of Legionaries remained behind, commanding fortifications they had built on countless worlds. When news of Roboute's betrayal reached them, these warriors resolved to fight against the Arch-Traitor to the last. They cost the traitors millions of lives to take, and more often than not, the fortress' commander had a plan to deny even that to the enemy by ensuring the fortress' self-destruction.

Despite the obvious cost of such a course of action, the traitors attacked the Iron Warriors' citadels wherever they found them, unwilling to let enemies in the back of their advance. The Imperial Fists especially engaged in a galaxy-wide punitive campaign against Fourth Legion's assets, though they never set foot in the Olympian system.

The most famous of these strongholds is the Shadenhold. Led by Warsmith Barabas Dantioch, it was a fortress located in an underground cavern of the world named lesser Damantyne. For more than a standard Terran year, Barabas held at bay a force composed of thousands of Legionaries, millions of mortal soldiers and several Traitor Titans with no more than a few Astartes and men under his command. When an Imperator Titan attacked and all things seemed lost, Barabas detonated the charges he had set at the basis of the descending spire into which he had carved the Shadenhold, killing thousands of traitors and destroying the Titan itself. The exact fate of Warsmith Dantioch remains unknown, as there are rumors that he escaped by teleporting in a traitor ship in orbit with his remaining men. Regardless of their truth, he was never heard of again in the Imperium, but his name became a legend among the Iron Warriors.

Perturabo also abandoned all notion of protecting the Throneworld's population. He focused all of his efforts and resources on the Palace itself. Perhaps he did so thinking that the traitors would only concern themselves with the ultimate prize, and ignore the mortals. Perhaps he truly did no longer care, his heart hardened by the unthinkable betrayal. But he made the Imperial Palace into a stronghold such as the galaxy had never seen before.

Malcador walked slowly, his body finally showing the signs of age he had avoided for so long. As he followed the Sigillite down the corridors of the keep, Perturabo wondered if that had anything to do with his father and brother disappearance in the Palace since his return to Terra. The two beings – the ageless genetic demigod and His most trusted advisor, a man preserved beyond his natural life by the power of a living divinity – passed before wonders of ages long gone, preserved by stasis fields. Perturabo saw the painting of a smiling woman whose eyes seemed to hide the truth of the universe; a slab of stone covered in scriptures from several languages he didn't recognize; and countless others. Finally, they came to an halt before a simple leather-bound book.

'The Emperor knows of your ... interest, shall we say, in the work of the one you and Magnus call the Firenzi Polymath, Perturabo,' said Malcador, his voice still strong and steady despite his frail frame. 'He knows, just as I know, that you have sought to make his designs a reality ... and have had a measure of success.'

Perturabo shrugged.

'I did my best, but there are still parts of his work I couldn't understand. It isn't that the schematics are impossible, but ...'

'More than they were incomplete, right ? ... But you will need more, if Guilliman's treachery is to be broken. The war will come here, Perturabo ... it is inevitable. You know it as well as I do, or as the Emperor does – or even as Roboute does. The Arch-Traitor can conquer all of the galaxy, but as long as Terra stands, he is not truly victorious. That is why he will come here, and that is why we must be prepared.'

Perturabo said nothing. There was nothing to add to the truth of the Sigillite's words.

'And that is why ... ' Malcador entered a deactivation code in the book's stasis field ... 'I believe this will be of use to you.'

The Siege of Terra

After years of bloody, unrelenting conflict, the forces of Guilliman finally reached the Sol system. When the first ships of the traitor horde emerged from the Warp, they saw that Perturabo had been far from idle while they burned his father's empire and murdered His subjects. Millions of traitors died in the first minutes of the assault, their ships utterly annihilated by the combined fire of hundred of outposts, the onslaught carefully arranged by the most gifted sons of the Lord of Iron to cause maximum damage.

Guilliman had foreseen the defences of Terra, however, and only placed ships he was ready to let die at the vanguard of his forces. The death of so many of his own allies, including an entire Chapter of his own sons, sacrificed in cold blood, was channelled by the sorcerers under his command to summon a horde of daemons that stormed the defences, allowing the rest of the fleet to pass. Thousands of loyal Space Marines stationed in these strongholds died fighting against the daemonic legions, their fate heralding what all of Mankind would suffer should Guilliman win. On Titan, the Sigillite's mysterious knights-errant held their ground, and it is said that they put down an abomination that would have turned the tide of the war, had it been allowed to reach Terra.

With nothing more remaining in their path, the Traitor Legions and their slaves descended upon the Throneworld in their millions, and the cradle of Mankind burned once more in the fires of fratricidal war. For weeks, Guilliman's forces struck at the walls of the Imperial Palace, while in orbit, the fleet of the traitors fought against the myriad defences Perturabo had installed. Horus, Perturabo and Mortarion led the defenders, the Warmaster and the Death Lord fighting alongside their warriors while Perturabo, much to his dismay, remained behind the frontline, commanding the loyalist forces' moves. The three Primarchs had decided that the Lord of Iron was the one best suited for this task, as the Emperor's Praetorian.

The loyalists fought on and on, following Perturabo's orders, while the traitors' assault dissolved into anarchy as the corruption of the Warp drove them into madness. This played to the loyalists' advantage, but Perturabo was horrified to see the degeneration of his brothers' Legions with his own eyes. And then, Horus Lupercal, Perturabo's most respected brother, died at the fangs of Sanguinius, once the most noble of them all.

Forrix watched as his father listened to the report from the Eternity Gates. The Triarch was frozen in place, unable to think, unable to act. He had already experienced that feeling – back when they had returned from Olympia, and learned that Guilliman had betrayed the Imperium. It was the sensation of one's universe being torn apart as something that was believed impossible suddenly happens.

Horus was dead.

Horus. Primarch of the former Luna Wolves, who had taken his name in homage of his service to the Imperium. First and greatest of the Emperor's sons. Warmaster of the Imperium of Man ...

'Send to the Sixteenth Legion to hold its position,' said Perturabo at last, freeing Forrix of his paralyzed trance. The Triarch looked again at the Lord of Iron. The face of Perturabo was neutral, as if what he had just been told was just another casualty in the war and not the death of his own brother. Most wouldn't have seen beyond that facade of calm, but Forrix was an Iron Warrior, and a Triarch. He knew his father more than any other soul in the galaxy, safe the Emperor and a few of His sons.

Perturabo may appear calm outwardly. Inwardly, he was screaming.

The loss of Horus drove the Sixteenth Legion into despair, and Perturabo was barely able to keep them from breaking there and then. Even so, he was forced to abandon entire sections of the Palace to the traitors' advance, and the renewed assault of the Blood Angels, who had thus far satisfied themselves in attacking the defenceless population of Terra, was threatening to overwhelm his defences. For a terrible moment, it seemed that all was lost, and then, from the absolute darkness of the void beyond the Sol system, came the Third and Eighth Legions.

The Siegelords' Duel

The arrival of the Night Lords and the Emperor's Children, combined with the destruction of Sanguinius at the hands of the Sons of Horus, seemed to turn the tides of the battle, but the final result was still far from certain. From his command bunker, Perturabo predicted what Guilliman's next move would be, and called for his brother Magnus to join him in the Imperial Palace. With heavy heart, he demanded that a small force of Astartes remain on the walls while he and his brother prepared for the inevitable moment when Guilliman and his cohorts would break in. The sacrificial force was led by Warsmith Kroeger, another of Perturabo's Triarch. With a thousand warriors, he held the gates of the Imperial Palace against the combined elite forces of three Legions for more than an hour before dying, it is said, under Rogal Dorn's own blade, cursing the traitor with his last breath.

Guilliman, Dorn and El'Jonson finally reached the interior of the Imperial Palace, accompanied by their best warriors. As they marched toward the Golden Throne, guided by the psychic resonance of the sacred engine, they met the last line of defence of Perturabo : the Cavea Ferrum, a labyrinth worthy of the legends whispered about it across a hundred worlds.

The Cavea Ferrum

Beyond the walls of the Imperial Palace, in the sections of the continent-wide building that were entirely destroyed and rebuilt by Perturabo, lies the Cavea Ferrum. To this day, it is the penultimate line of defence of the Emperor, just before the Custodians guarding the Golden Throne itself.

The Cavea Ferrum is a wonder of architecture, based on designs from Old Earth and brought into existence by the genius of the Lord of Iron. It is a labyrinth that defies all attempts to map it, seeming to violate the laws of physics through the use of mathematics and theories that normal minds would struggle to even conceive. Even an Astartes' or a Primarch's mind will be unable to navigate across it without knowing the paths, and even then, following the counter-intuitive and seemingly random turns is very difficult. Today, only the Custodians themselves journey through the Cavea Ferrum, though whether or not they understand its logic is unknown to all but the Emperor's own guards.

Guilliman could find his way through, but he had underestimated Perturabo's cunning. The force he had led was separated, and the Lion and Rogal were led to their two brothers by twisting echoes and taunting whispers. There, Lion El'Jonson faced Magnus the Cyclop, released from his duties in this final hour, while Rogal Dorn met Perturabo, in what was to be the first time the rival Primarchs actually fought each other in battle.

Since that fateful night in Lochos' banquet room, he had always held back his temper.

When his sons had died by the hundred under the guns of the foolish and the xenos, he had held back, redirecting his anger toward better planning and strategy. When his world had burned in the fires of treachery, he had held back his rage, channelling it toward the salvation of as many of his people as he could. When his brother had died, he had held back his grief, turning his mind to the accomplishment of the duty the dead Warmaster had given to him.

No more. As he locked his eyes with his brother and saw only hatred and bloodthirst, Perturabo of Olympia let go of all his restraint, of all his self-control. He let the fire of his rage course through his veins freely, like a great river bursting forth after a dam is broken. Unlike the madness that raged within his brother's soul, this was no mindless anger, no surrender to the beast inside. It was the forsaking of all pretense of civilization, the embrace of his true nature as an agent of war and death. He was no longer Perturabo, the builder, the scholar, the benevolent ruler and bringer of unity, the craftsman who would spend hours in his workshop, creating wonders.

He was the Lord of Iron, and he was going to kill Rogal.

He lifted Forgebreaker, the great hammer that had been bestowed upon him by Horus when he had returned to Terra, and charged his brother in complete, deadly silence, with a thousand curses in his mind and death in his eyes.

The two Primarchs fought for several hours, Rogal Dorn's fury matched by Perturabo cold, cold anger. They bloodied each other many times, until finally, word reached the two of what had transpired in the Throneroom. Fulgrim was here, and Guilliman was dead. The Ultramarines were running. Screaming in rage, Rogal dealt a final blow to Perturabo, throwing down the Lord of Iron, but before he could finish him, Perturabo's sons gathered to protect their fallen father. It seemed as if the lord of the Imperial Fists intended to kill them all, but at the word of his First Captain, he decided to leave Terra before it became impossible.

Rising from the ground, Perturabo ran to where his father had faced and slain Guilliman. The Praetorian found the Emperor dying, and, together with Magnus, placed Him upon the Golden Throne before activating the stasis field and consigning his own father to what he knew to be an eternity of pain in the greatest sacrifice of all Mankind's long, bloody history. It is said that even as the Lord of Iron worked on the wondrous mechanisms of the Golden Throne, his genius mind understanding its workings with ease, his composure never faltered. Only after Magnus confirmed to him that their father was now secure did he begin to weep for all that had been lost.

Post-Heresy : The Iron Cages

My brother killed my dreams.

I look upon what the Imperium has become, and I have to hold back my tears. Why, Roboute ? Why ? I saw your kingdom of Ultramar during the Great Crusade. Five hundred worlds united under your aegis, a model of what Mankind could achieve. I saw the courage and honor in the heart of your people, their conviction and strength. Unity in the name of an ideal of peace and illumination. This was what the Imperium could have been, and you betrayed it all for the promises of daemons and the lies of false gods. Now the Imperium as I – as our father – saw it, is dead, and what stands in its place is a mockery of the ideals we fought so hard to make real. With your treachery, you have poisoned the soul of Mankind itself, and tyranny and oppression are now our only path we can follow that will let us survive in an universe that hates us.

There is still nobility, still purity in the Imperium as it is today, but I am no fool. I never was, though now I wish I was. Then perhaps I wouldn't see the future of this empire as clearly as I do now. I see only ruin for Mankind in the future. Only war, war without end, until the day the light of the Astronomican falls dark and the galaxy is drown in humanity's blood.

Yet I will stand. I will fight. I will not let my doubts show. My sons deserve better than a father plagued by uncertainties, and every century of battle buys a few more generations time to live, a few more billions the right to live in relative peace.

Is it worth it, though ? Sometimes, I ...

From the private writings of the Primarch of the Fourth Legion, unfinished.

In the immediate aftermath of the Heresy, the Iron Warriors joined in the effort of rebuilding the Imperium. Their skills as builders were almost as useful in these times as they had been during the Heresy itself, as the sons of the Fourth Legion were responsible for the reclamation of hundred of worlds that had either been lost to the traitors' invasion or had outright allied with them. The Iron Warriors also build thousands of strongholds across the galaxy in this era, which are still standing in this day and are some of the most important strategic assets an Imperial commander can hope to have in a war zone.

After the galaxy was purged from the Traitor Legions' remains, the Iron Warriors choose to guard the gates of the two hellish underworlds into which their wayward cousins had retreated. The rest of the Imperium saw this as foolishness, and a waste of resources that could better be used elsewhere. But Perturabo was adamant, and no Lord of Terra ever managed to convince the Primarch of the Fourth Legion that surely, the traitors were dead, destroyed by the madness that holds sway in the Ruinstorm and the Eye of Terror. Now, of course, we know that he was right.

A giant belt of outposts was created around the two Warp Storms, with entire worlds turned into strongholds at the points where the Traitor Legions could escape from their prison. Cadia, once a world of lavish jungles and a profusion of life, was turned into a single giant citadel. A garrison of Iron Warriors was constantly stationed at the Cadian Gate, ready to fight off any Chaos raiders attempting to flee their exile. The twin circles that surrounded the galactic hells were called the Iron Cages, and the Fourth Legion took upon itself to guard them forevermore. Many forces from other Legions would come to their aid during great invasions from the Eye and Ruinstorm, but it would always be the Iron Warriors who stopped the initial assault with their fortresses and ships, taking heavy losses to prevent the traitors from reaching the rest of the Imperium.

In this forty-first millenium, the Iron Cages have come under attack from another enemy, one Perturabo couldn't have possibly foreseen. The Tau, a race of xenos from the Eastern Fringe, have risen to conquer a significant portion of the region, and their expansion has brought them dangerously close to the Ruinstorm. Whether it is because of pure stupidity or an hidden agenda, the Tau have launched several attacks on Iron Warriors' outposts in the region, apparently not realizing that their actions could unleash the Ultramarines upon themselves. In recent years, the Triarch in charge of the Ruinstorm's oversight has called for a massive crusade against the Tau, in order to wipe them out entirely before they can seriously damage the Iron Cage keeping Guilliman's bastard sons at bay.

Honsou watched the enemy forces approach, standing atop the walls of the Hydra Cordatus bastion. The Raven Guard had come in numbers, reflected the young Iron Warrior. Then again, what else to expect from the Traitor Legion that specialized in genetic atrocities, breeding monsters to fill its ranks even if it meant degrading their own bloodline even further ? Numbers were about the only thing they had for them, and even then they had had to drag millions of mortal slaves to the world they hoped to take. Praetorian's name, they could try if they wanted. This was one of the greatest Iron Warriors' fortress, built to house and protect one of their most precious progenoid storage and cultivation facilities. Nothing could break these walls ...

Something in the sea of enemies caught Honsou's attention. A figure, creating order in the middle of absolute confusion. A great, towering silhouette, far too distant for him to have been able to see it and yet impossible to miss. It had suddenly appeared in the middle of a vast circle, traced upon the rock by witchcraft and fueled by arcane symbols and the blood of thousands of prisoners.

The creature was impossible to describe in any way that made sense. It was shrouded in shadows and radiated dark light; it was the incarnation of death and a perversion of life; it shrieked in silence, yet its voice – which he could hear even here, on the parapet – was the herald of the End Times. He knew this creature, though he had never thought he would ever see it. It couldn't possibly be here, yet it was equally impossible for it to be anything else than what he thought it was.

Honsou turned, and started to descend the wall, already trying to reach his commander over the vox. He had to warn the other defenders. Warsmith Shon'tu had to be told.

Corax was here.

Organisation

As time passed and Perturabo fought on and on in the many wars of the Imperium, eventually the Primarch accumulated too many wounds. He lost his right arm in the battle of Sebastus IV, where he faced Rogal Dorn for the final time – banishing the Daemon Primarch back into the Eye after he had escaped it at the head of a massive fleet. His left eye was torn out by a Dark Eldar warlord on Corusil V, after months of a brutal, grueling campaign. Wound after wound forced Perturabo to increasingly rely on augmentics, until the battle of Ularan in late M32, where he was finally entombed into a Dreadnought.

Ever since that time, Perturabo has slipped in and out of trance-like rest, and his periods of sleep have grown ever longer for each one of activity. To balance the loss of leadership, he gave far more reaching authority to his Trident, as well as the right to choose the replacements to their fallen members if one of them died while the Primarch was asleep. Since then, the three members of the Trident have shared command of the Fourth Legion, one of them remaining on Olympia, another on Cadia, and the third surveying the borders of the Ruinstorm.

Beneath the Triarchs are the Warsmiths, who assume a rank similar to that of Chapter Master, Magnus, or Great Captain in other Legions. Each one of them commands a Grand Battalion, the strength of which depends upon his assignments. Some Warsmiths command a single Company, protecting a world against xenos raiders. Other can lead thousands of Astartes into the greatest wars the Imperium is fighting at the moment.

Beliefs

'From Iron Cometh Strength. From Strength Cometh Will. From Will Cometh Faith. From Faith Cometh Honor. From Honor Cometh Iron.'

The Unbreakable Litany

Before the Heresy, the Iron Warriors were the defenders of Mankind, seeing themselves as the guardians of the countless trillions citizens of the Imperium as they rose toward an utopia never before achieved. The dream that Perturabo had shared with his father – to create a civilization of true freedom, freedom from the Warp's corrosive touch, freedom from the petty whims of tyrants, freedom from the darkness lurking in the stars – was one of true nobility and purity. But that dream was destroyed when Guilliman first pledged his allegiance to Chaos.

As their Primarch slowly fell into melancholy, the Iron Warriors grew bitter. They had lost what had truly mattered to them : a cause worthy to fight for. The survival of Mankind was something that had be preserved, yet it was far from being as inspiring as the Great Crusade had been. The belief in Mankind's rise to utopia was crushed as they watched the Imperium grow increasingly tyrannical over the centuries, forced to promote ignorance and fear where it had once brought illumination and peace.

Yet despite their growing unrest, the Iron Warriors endure. They do their best to ensure the worlds under their command remain as close to the Crusade's ideals as they can, and fight the eternal wars so that no other will have to. The fact that, contrary to prior the Heresy, the Fourth Legion is largely aknowledged by the Imperium's people for its efforts and sacrifice – due to their spread out presence across the galaxy in their strongholds – helps them keep faith in Humanity. They have also embraced the faith of the Emperor more than Legionaries tend to, and many believe that the Emperor will one day return to lead Mankind to glory and paradise once more. Until then, it is their duty to protect the Imperium, and they do not intend to fail.

Combat doctrine

Most Legions use tactics of precise strike, in following to the 'spearhead' strategy favored by Warmaster Horus himself, and still used by his sons to this day with great success. Due to being an elite force, and often present in small numbers, the Astartes specialize in identifying and attacking key targets, be it enemy officers or strategic locations. Not so for the Iron Warriors.

When the Fourth Legion goes on the field rather than defend its countless fortresses, it does so with overwhelming numbers. Thousands upon thousands of Legionaries wearing the grey and yellow of the Iron Warriors, with engines of death the size of building and entire Imperial regiments at their side. The sons of Perturabo fight on a planetary scale, taking command of the entire stage when they arrive – or grudgingly deferring that authority to the Warmaster, if one has been named. To see a Fourth Legion's deployment is an awe-inspiring sight. Their mastery of logistics is beyond anything seen in the Administratum, and more than one rebelling world has simply surrendered after seeing row after row of tanks prepared to crush its cities' walls.

The Iron Warriors also have a very close relationship with the Adeptus Mechanicus, going back to the Martian Wars. They are one of the few Legions to be able to call upon the Legio Titanicus and be sure the god-machines will answer their call. Forge-worlds under their protection will not hesitate to entrust them with their skitarii forces.

The Last Chance

A tradition in the Fourth Legion, said to have been installed by Perturabo himself, is to always offer the enemy a chance to surrender. Whether the foe is a rebel, a xenos, or a Chaos-damned traitor, most Warsmiths will make sure that the enemy is given the opportunity to throw down its weapons before beginning the battle. However, in most cases, that offer is refused, and in the rare cases it isn't – mostly when facing rebels with genuine griefs against local corruption and terrified by the sight of the Legionaries – the sanctions inflicted upon the enemy are severe.

Homeworld

Olympia was first settled during the Dark Age of Technology. At that point, it was a world rich with ore, but by the time the first Warp Storms plunged the galaxy into the Age of Strife, it had been stripped of all its valuable resources to feed the ever hungry forges of other planets.

Now, the world is a jewel of civilization, shining its light in the darkness of the galaxy in defiance. Great cities modeled after Perturabo's own schematics cover its surface, and it is surrounded by a ring of orbital defences that have not been pierced once in ten thousand years. Protected by the Legion, Olympia is the last echo of Perturabo's dream. Its surface, devastated during the war against the Hrud, was restored by the masons of the Fourth Legion, while the great shipyards that orbit around the world had to be rebuilt from scratch and what little wreckage of their precedent incarnation had been found on the world.

The surface of the world is still similar to what it was during Perturabo's youth : a collection of city-states, bound by a common allegiance to the Iron Warriors and dedication to the Emperor's will. It is mostly from their ranks that the Legion recruit not just its members, but also the countless servants that allow it to function, as well as its auxillary regiments. The more material needs of the Iron Warriors – ammunition, heavy support, and ship's maintenance – are cared for by the orbital decks and the other worlds of the system, turned into forge-worlds by the portions of the Mechanicum who allied with Perturabo in times now long gone.

Recruitment and Geneseed

In the era of the Great Crusade, most recruits of the Iron Warriors came from Olympia itself. Now, with the Legion so thinly spread, each Grand Battalion is responsible for its own recruitment, though the homeworld still pays its tithe of young men. Children from the various worlds under Iron Warriors' supervision are induced, as well as some born in the Imperial Army's regiments assigned to fight alongside the Fourth Legion.

When the first warriors of the Fourth Legion were inducted on Terra, at the beginning of what would become the Great Crusade, the rates of implant rejection were very low. This enabled the Legion to grow in number very quickly, and in the years to follow, to replenish its losses more efficiently than other Legions. Perturabo's gene-seed was devoid of any impurity, and despite some Warsmiths pressing their Apothecaries for quicker replacements for their losses, its quality was preserved throughout the Great Crusade and the nightmare of the Heresy. But that changed after the creation of the Iron Cages.

With most of their warriors stationed so close to the two greatest Warp Storms of the galaxy, the Iron Warriors began to suffer the consequences of their devotion to their duty. Mutations spread across their ranks, subtle but nonetheless there. It became common practice to remove mutated organs and replace them with augmentics, or cloned flesh from previous tissue samples. Progenoid glands are destroyed when the mutations are too pronounced in a Legionary, but this threatens the continued existence of the Legion itself. The ability of the Iron Warriors to obtain fresh genetic material from their Primarch has diminished ever since his entombment, for while it is still possible, the Dreadnought which hosts his remaining flesh is more complex than any other in the Imperium, and the Techmarines of the Legion do not want to risk damaging it. Still, the fear that they may be slowly damning themselves by doing their duty has added one more concern to the ever-growing list of griefs that the Iron Warriors have accumulated over the millenia.

Warcry

The Iron Warriors have kept the same battlecry since the Heresy : 'Iron within, Iron without !'. When facing members of the Traitor Legions, they also use 'For Terra and the Praetorian !' in memory of the Siege. As a rule, however, Perturabo's sons are no adept of such emotional display on the battlefield, preferring to focus their minds on the hundred calculations of war or on the enemy in front of them.