The Iron Blood was an Imperial Gloriana-class Battleship that served as the flagship of Perturabo, the Primarch of the Iron Warriors Legion, during the Great Crusade and the Horus Heresy in the late 30th and early 31st Millennia. At nearly twenty kilometres in length, unbreakable strength and brute firepower, the Iron Blood 's craggy flanks were clad in armour tens of metres thick. She was without viewports, for the war doctrines of Perturabo made it clear the battle should be conducted by calculation and firepower, and viewports into the void war were nothing but vanity. This flagship rode at the head of a flotilla of the Iron Warriors' warships which comprised the IVth Legion's Imperial Expeditionary Fleet. The Iron Blood is known as the oldest and mightiest of her class, constructed at the orbital shipyards of the Iron Warriors' homeworld of Olympia at the order and to the exacting specifications of Perturabo himself. The prow of the Iron Blood resembled a vast iron arrowhead, followed by a crenellated hull behind it. Her slab-like armoured flanks were blackened by the fires erupting from the carcasses of dying foes smashed asunder by brutal ramming attacks, and her serrated spine was a mountain of bristling weapons turrets of all types. Weapon batteries also lined its sides. At the time of the Great Crusade, it was considered one of the mightiest capital ships in the galaxy, capable of single-handedly annihilating other void fleets and entire worlds.
The Iron Blood is notable for taking part in the Battle of Phall, a major void engagement that took place following the start of the Horus Heresy in the early 31st Millennium after the Istvaan III Atrocity, between the entirety of the Iron Warriors Legion's fleet and a formidable Imperial Fists Legion Retribution Fleet. Perturabo was sent by the Warmaster Horus to halt the encroaching Imperial Fists fleet that had originally been sent to Istvaan III by their Primarch Rogal Dorn to reinforce the beleaguered Loyalists trapped on that world. The Traitors could not allow such a strong complement of Astartes to infiltrate their controlled area of space, for the Loyalists' presence would seriously disrupt preparations for the Traitors' drive on Terra. Commanding the entirety of his Legion's war fleet, Perturabo led his warships in a sudden and devastating attack upon the Imperial Fists' fleet in the nearby Phall System where the Loyalists had massed for the attack on Istvaan.
Ultimately Perturabo failed in his attempt to annihilate the entirety of the Loyalist fleet, due to the vigilance and foresight of Captain Alexis Polux, the commander of the Imperial Fists Retribution Fleet, who had kept the warships under his command at a high state of combat-readiness. Though they sustained significant damage, Captain Polux was able to launch a successful counterattack against the Iron Warriors' fleet and inflict significant damage as well as destroy or disable multiple capital ships. When the Retribution Fleet's Astropaths finally managed to make contact with Terra, they received a direct order from Rogal Dorn recalling the Retribution Fleet to Terra to prepare the defences of the Imperial Palace. Launching a bold counter-strike, the Imperial Fists drove off the embattled Traitor fleet and managed to break orbit and manoeuvre to their jump points, where they entered the Warp and made for Terra to prepare for the Traitors' coming assault upon the homeworld of Mankind.
The oil-scented hallways of the Iron Blood gleamed with freshly applied unguents. Corridors crossed vaulted processionals of ranked artillery pieces, with hundreds of heavy armoured vehicles suspended on massive chains from the strengthened roof trusses. Great spiral stairs wound themselves around thunderous columns of magma-hot power, and super-hardened magazines packed tightly with shell casings, entrenching gear and millions of rounds of volatile ammunition. More than any other Space Marine Legion, the interiors of Iron Warrior vessels were given over to supply and logistics, for their way of war depended on a steady supply of high-explosive warheads.
It was very easy to become lost while travelling through the guts of the massive starship. A notable feature of the Iron Blood was that it had no viewports. There was no need for them, or so many witnesses had heard Perturabo say. The Iron Warriors' Primarch felt that one did not need to look at the void. War in space was a matter of calculations, sensors and firepower. That or hacking your enemy apart in spaces so small you could smell their blood. Windows that allowed one to look into the void were a weakness indulged for vanity.
The frontal sections of the warship were all but abandoned. As one travelled further into the massive vessel the high-walled chambers of hot iron and sweating pipework through which an individual passed became ever more cramped as more and more space was given over to the prow weapon systems: the vast tubes of the forward torpedo arrays and power relays serving the heavy gun batteries mounted to either side of the carved ram of its bow.
Housed amidships had been the Remembrancer decks. These cramped living spaces were utilised by the members of the Imperial Remembrancer Order that accompanied the various Expeditionary Fleets of the Great Crusade. Their function was to chronicle all the glorious deeds of the Space Marine Legions and the Imperial Army in the course of the Crusade so that the future posterity of the Imperium of Man would know how humanity had come to dominate the galaxy. The Expeditionary Fleets led by the Astartes very grudgingly accepted them aboard the starships of their fleets. Showing the common disdain for journalists held by warriors of every generation and era, the Remembrancers were generally disliked by the Primarchs, the Astartes and the line troops of the Imperial Army. The interior of an Iron Warriors voidship was always a hard-edged, functional environment, with little in the way of superfluous space, but these decks reeked of abandonment. The thousands of Remembrancers that had attended the Legion in the latter days of the Crusade had lived and worked there, but they were all gone, and none of the IV Legion made use of those dark spaces. Scraps of the Remembrancers' graffiti still lingered on the walls, snatches of poetry, pornographic caricatures and hastily drawn musical scales, but many were now obscured by bloody handprints and spattered arcs of dried gore following their massacre at the hands of their Astartes hosts following their turn against the Emperor and pledge to follow the Warmaster Horus into rebellion.
Located within the vastness of the forward prow of the Iron Blood was The Dodekatheon, the seat of the mason's order of the Iron Warriors Legion which had been gathering aboard Iron Warriors starships even before their Primarch Perturabo had been reunited with his gene-sons. It was a meeting place of builders and warriors, where new structural designs were unveiled, past battles refought and new theorems of war given voice. Every warrior of the IVth Legion was welcome, but in practice only those of rank had the opportunity to attend any of the lodge meetings. Here, Iron Warriors pored over sheaves of architectural plans, while others clustered around hololithic displays projecting schematics of wall details, projected bombardment patterns and fire schedules. Hundreds or so warriors would usually be assembled, some in armour, some in their mesh and mail robes. Though it appeared quite informal, this place was as much of a vipers' den as ever one might imagine. Alliances were made and broken here, pacts and oaths sworn and forgotten before a night's end.
It was all very useful, to see who favoured whom and where plots were formed, was knowledge that would stand an individual in good stead when it came to deciding upon the order of battle. Pitching any three Warsmiths into battle alongside each other was always good to foster some healthy rivalry between them. Judging the right level of rivalry could spur each Warsmith to greater heights of endeavour, just as getting it wrong could cause an army to fight itself as much as the enemy. Often times, the Iron Warriors would show a gesture of cooperation between Legions, by inviting a brother Legion's warriors to their order. In turn, they would send one of their warriors to the other Legion's Warrior Lodge, if one existed.
The vast command chamber of the Iron Blood had rivet-stamped beams which arched up to a cross-latticed vault hung with empty bird cages, and the thrum of powerful machinery echoed in the depths of the walls. Dusty banners and tattered maps of Old Earth were hung with strips of oath paper, recording victories no one beyond this room could name and of which no Remembrancer had ever taken note. Perturabo's throne of cold iron, crafted from the molten remains of his adopted father's treasury, stood empty at the far end of the chamber beneath high lancet windows of latticed armourglass that looked out onto whatever new world the Iron Warriors Expeditionary Fleet would next bring into Imperial Compliance. Bare girders columned the bridge of the Iron Blood, and bolted gantries stacked above one another ran the length of it, each filled with augmented Servitors to man the more mundane elements of the ship's operation. A handful of Iron Warriors manned the stations requiring post-human input.
- Captain Bahdet Vort - The Iron Blood 's captain was a mechanised cybernetic hybrid named Bahdet Vort. He was responsible for the overall command of the vessel and maintaining the voidship's course and trajectory through both realspace and the Warp. His body was largely subsumed into the devotional command altar from which the vessel was steered. Vort relayed a steady stream of correctional data to the acting Iron Warrior commander in charge of the watch.
- The Horus Heresy - Book Three: Extermination by Alan Bligh, pp. 52-53
- Shadows of Treachery (Novel), "The Crimson Fist," by John French, pp. 25, 38, 41, 43, 45-47, 49, 54
- Angel Exterminatus (Novel) by Graham McNeill, pp. 31, 34, 78, 81, 119-121, 134, 139, 141-142, 145-146, 169, 173-174, 176, 179, 193, 195-197, 202, 284