We may earn a commission when you buy through links in our articles. Learn more.

Warhammer 40k Iron Warriors - Iron Within, Iron Without

The traitor Chaos Space Marines of the Iron Warriors legion are a bitter, paranoid brotherhood of siege masters and daemon-binding warpsmiths

Iron Warriors Space Marine holding a missile launcher, painted by Gonders

The Warhammer 40k Iron Warriors are a brutal and callous legion of Chaos Space Marines. Clad in armour of dark iron trimmed with gold and ornamented with black and yellow hazard stripes, they’re masters of siege warfare. Our guide explains their rules in Warhammer 40k, and the bitter history that brought them to rebel against the Emperor.

The Iron Warriors favour heavy ordnance, and in their redoubts within the Eye of Terror their many Warpsmiths have mastered the art of binding daemons to create Daemon Engines. The daemonic techno virus that creates Chaos Space Marine Obliterators originated within their legion – many such man-machine hybrids are found in their warbands.

Iron Warriors Obliterators - model photographs by Games Workshop of a pair of Obliterators, huge, partly daemonic entities with guns and armour bursting from their flesh

Iron Warriors are bitter at heart and inured to suffering, holding all others in contempt. Some seek the gifts of the 40k Chaos Gods as another mighty tool in their arsenal, while others rebuke them as an admission of weakness.

If that doesn’t sound like a good fit for you, we have a guide to all the Warhammer 40k factions to help you decide which army is for you – whatever you pick you’ll spend a lot of time painting miniatures from the range, so it’s good to be sure!

Iron Warriors army painted by Gonders - a force of infantry, terminators, a spartan assault tank and dreadnought

Iron Warriors Army in Warhammer 40k

Like all their traitor brethren, rules for the Iron Warriors army are found in the 9th edition Warhammer 40k Codex: Chaos Space Marines. Iron Warriors are used to taking punishment and are quite resilient, something they supplement by pushing waves of cultist cannon fodder in front of enemy guns. Their own guns are mighty indeed, and they bolster their mundane ordnance with possessed Daemon Engines and warp-infused daemonkin.

Iron Warriors Helbrute - a warp mutated walker vehicle with exposed flesh, armour silver with gold trim and black and yellow chevrons

Iron Warriors Legion Trait

The Iron Warriors Legion Trait emphasises their role as siege breakers, able to weather the storm of enemy fire when they force a breach, while targeting foes in heavy cover with an expert eye. Targets of Iron Warriors attacks never receive the benefit of cover. When an attack with an AP of -1 or -2 wounds an Iron Warriors unit, they worsen the AP by one.

Iron Warriors cultists – cannon fodder

With the legion entirely indifferent to the lives of its mortal vassals, Iron Warriors cultists are doomed to a short existence, herded towards enemy kill zones to soak up bullets. You can recreate this on the tabletop with some handy stratagems!

The Cannon Fodder stratagem costs 2CP and allows you to pair up an infantry unit (say, some heavy-weapon toting Havocs) and a cultist unit within 6” at the start of an enemy shooting phase. As long as the cultists are closer to the enemy than the unit they’re shielding, enemy models can’t target the shielded unit.

Don’t forget the basic Chaos Space Marines stratagem Contempt Over Caution, which allows you to fire into a melee, at the risk of inflicting wounds on your own embattled troops. If the friendly unit tied up in the combat happens to be cultists, this Stratagem costs only 1CP.

Iron Warriors predator tank - a battered silver battle tank

Iron Warriors firepower

The ability to deprive enemies of the benefits of cover means Iron Warriors firepower is never diminished by enemy defences. That’s especially useful in Boarding Actions missions from the Arks of Omen expansion, as models tend to have cover almost continuously in the cramped confines of a space hulk.

Two stratagems further bolster their dakka.

Stratagem Phase Target Effect CP
Tank Destroyers Your Shooting or fight phase Enemy vehicle unit Unmodified to-hit rolls of six by Iron Warriors Heretic Astartes units against the target automatically wound One
Methodical Annihilation Your Shooting phase Iron Warriors unit Re-roll one damage roll.
Count double the number of enemy models when determining the shots of Blast weapons.
Can fire Blast weapons against enemies in engagement range at the risk of suffering mortal wounds.

Tank Destroyers is the bane of Lords of War vehicles, allowing you to wound Imperial Knights with the humble bolter (or, more likely, the arrogant Reaper Chaincannon). Methodical Annihilation boosts the reliability of blast weapons but, perhaps more importantly, allows a Forgefiend or Vindicator without any melee weapons to violently extricate itself from melee by firing its guns at point-blank range.

Three different Warlord Traits can further boost Iron Warriors offensive power, each of them allowing your Warlord to nominate a unit within 6” during the Command Phase and grant it a combat bonus until the next Command phase.

Iron Warriors Helbrute - a warp mutated walker vehicle with exposed flesh, armour silver with gold trim and black and yellow chevrons, with a missile launcher and twin lascannon

Siege Lord increases the damage characteristic of high strength weapons a friendly core or vehicle unit is wielding when they target a suitable vehicle or building target. Though there’s a reasonable narrative justification for this not affecting monsters, against Tyranids or a battlesuit heavy T’au Empire army this is a completely inert ability.

Daemonsmith grants a simple +1 to hit on attacks made by a Daemon Engine, Cult of Destruction, or Machine Spirit unit, while Architect of Destruction allows a Core or Vehicle unit to count as being in Wanton Destruction, gaining additional hits with heavy weapons on to-hit rolls of six, even if your army has moved onto acts of Wanton Massacre or Wanton Slaughter.

While there are probably cleverer things you can do with an Iron Warriors Warlord, Daemonsmith and Architect of Destruction as effective as they are unsubtle – very on theme.

Iron Warriors Chaos Space Marines army advances - diorama photograph by Games Workshop, silver armoured Space Marines advance alongside tank support into enemy territory

Iron Warriors durability

Iron Warriors durability is increased greatly by their Legion Trait. It provides them with solid protection against small arms fire, effectively granting them the Armour of Contempt ability that all power-armoured troops enjoyed during Warhammer 40k Matched Play in 2022. They also benefit from several defensive stratagems.

Stratagem Phase Target Effect CP
Dour duty Any Iron Warriors Core or Iron Warriors Daemonkin Subtract one from the damage characteristic of attacks allocated to Heretic Astartes in the unit Two if target power level 10 or more, otherwise one
Unholy vigour Any Iron Warriors Machine Spirit or Iron Warriors Daemon Engine Subtract one from wound rolls made against the unit Three if target is titanic, otherwise two
Spiteful endurance Any Iron Warriors Heretic Astartes Ignore mortal wounds on a 5+ One

Iron Warriors Primarch Perturabo, illustration by Games Workshop of a warrior in massive armour

Iron Warriors Primarch – Perturabo

The Iron Warriors Primarch Perturabo was created in the genelabs of the Emperor of Mankind, and like all his superhuman brethren his gestation pod was hurled into the warp by the machinations of the Chaos Gods. He landed on Olympia, a world of eternal dynastic struggles between city-states built around nigh-impregnable mountain fortresses.

Perturabo was adopted by one of the planet’s Tyrant rulers, pledging loyalty in exchange for protection and tutelage in the arts of war. Perturabo became a masterful strategist, a genius inventor, and a paranoid politician – but there was no love shared between him and his father.

Adopting the title Lord of Iron, Perturabo led his city-state to victory after victory, cowing the rest of the planet into submission. Curiously, he never usurped his adopted father. When the Great Crusade arrived at Olympia, Perturabo accepted his role in the Emperor’s plan, assuming command of the IVth Legion Astartes, who he dubbed The Iron Warriors.

The Adeptus Astartes gene-seed derived from Perturabo’s DNA was particularly robust, and the legion had sustained a high recruitment rate as a result. Renowned for both resilience and dependability, the Iron Warriors had been used by Imperial Commanders unimaginatively, and their star had risen little throughout the Great Crusade.

Perturabo was displeased. It was not enough that his Legion should perform their duties well – they must excel, be without equal. His remedy for the perceived weakness of his legion was characteristically callous and decisive. He sentenced his Legion to decimation: one in every ten marines was to be executed by his brothers.

Perturabo pushed his sons hard and fast. Uncaring in the face of certain death, and led by a genius for whom every battle was an equation to be solved with the lives of his troops merely one more factor, they were especially skilled as siege breakers, able to force victories atop mounds of their own dead. Unsurprisingly, this won little favour among mortal commanders, who rightly feared their fates under Perturabo’s command.

Warhammer 40k Iron Warriors with rotor cannons, a squad of five silver-armored warriors with man-portable miniguns, painted by Gonders

Despite their relentless dedication to the cause, the Iron Warriors never received the recognition Perturabo considered their due due. Many of his legionaries were relegated to garrison duties throughout the Imperium, and other legions were lauded ahead of them by propagandists and artists.

Perturabo could never fully trust his brother Primarchs, who he saw as vainglorious peacocks, though he had common ground with some – the Warmaster’s genius for conquest, Fulgrim’s pursuit of perfection. He held Rogal Dorn in particular disdain, and the pair almost came to blows when, at a formal dinner, Dorn declared he could build a truly impregnable fortress and Perturabo vehemently disagreed.

Perturabo’s last loyal act was the repacification of Olympia. The planet attempted to secede from the Imperium of Man – with brutal finality, Perturabo’s legion scoured it of act.

Iron Warriors Deredeo Dreadnought - a walker vehicle with massive shoulder-mounted cannons and back-mounted rockets

Iron Warriors 30k – the Horus Heresy

Perturabo was able to test his boasts against Rogal Dorn when Horus Lupercal turned traitor on the Emperor and began the galactic civil war known as the Horus Heresy. The Iron Warriors joined the Imperial retribution force dispatched to crush the Warmaster’s rebel legions on Istvaan V, forming the second wave of the assault force.

Unbeknownst to the loyalists, the Legions in the second wave had all already declared for the Warmaster. The guns of the Iron Warriors rained iron death onto the embattled Salamanders, Raven Guard, and Iron Hands, nearly annihilating the three legions.

Iron Warriors tank column - diorama by Games Workshop of many Iron Warriors tanks, from light Predator battle tanks to huge super-heavy siege tanks

The Iron Warriors fought across much of the Imperium throughout the Heresy war. An early thrust towards Terra by the Iron Warriors was thwarted by an Imperial Fists retribution fleet, the failure of his Legion shaking Perturabo so badly that he dismissed his Space Marine bodyguards and replaced them with hulking Iron Circle Automata.

Fulgrim solicited Perturabo’s aid on a quest into the Eye of Terra, in pursuit of an Eldar artefact that grant them unparalleled power. Only one of them would claim the prize, and Fulgrim left with the gift of Daemonhood, while Perturabo grew yet more bitter and paranoid.

The Iron Warriors fleet arrived in the skies above the world Tallarn, a planet of minor value in the wider war, but with considerable reserves of armour and undeployed regiments in underground bases. Why Perturabo chose this target was never known to the loyalists.

The Iron Warriors virus bombed the planetary surface with such vehemence that even an Astartes warrior in full battle plate could not survive on the surface without succumbing to the toxins. Yet some survived in the underground bunkers, able to mobilise in tanks and take to the planet above.

Iron Warriors Land Raider - a heavy assault vehicle with silver armour, massive sponson mounted lascannons, and hull modifications

After word of the fate of Tallarn reached the Imperium, forces were drawn in from wider battle spheres. The planet became the site of the single largest tank battle in Imperial history, consuming materiel on both sides almost without cease – until the Iron Warriors withdrew, perhaps driven away, or their goal perhaps achieved.

Perturabo was a faithful servant of the Warmaster. His legion held the rearguard against Guilliman’s Ultramarines while the traitor forces mustered at Ullanor for the assault on Terra.

Though increasingly paranoid, he was still one of the sanest among the Warmaster’s increasingly chaotic forces, and was even able to corral the daemon Primarch Angron and his World Eaters sons away from acts of wanton slaughter and towards the grand assault on Terra.

Perturabo’s reward from the Warmaster for his loyalty was the honour of masterminding the siege of Terra. With guns, guile, and the growing shadow of the Dark Gods, Perturabo reduced the Palace of the Emperor and Rogal Dorn’s mighty defences stone by stone, warrior by warrior.

Iron Warriors quad mortar team, two silver armoured space marines with a self-propelled artillery piece - painted by Gonders

Iron Warriors and the Cage of Iron

After the death of Warmaster Horus and the defeat of the traitor forces at Terra, the Iron Warriors fell back from the territory they had claimed grudgingly, making the loyalists pay in blood. Their defiance was bitter and spiteful, and never more so than at the Cage of Iron.

Perturabo constructed a mighty defensive work on the world of Sebastus IV which he dubbed the Eternal Fortress. This structure had all the appearance of a last redoubt, a bastion around a hardened strategic command centre, designed to withstand an indefinite siege by the Imperial Fists. It was nothing of the sort.

The Cage of Iron was a trap, filled with kill zones, undermined by secret passages that allowed reserve forces to encircle and destroy any enemy breakthrough. The central command zone was utterly vacant, an empty decoy. The whole structure had one purpose only – to murder the sons of Dorn.

Iron Warriors land raider tank conversion by 40k Steve - an armoured assault vehicle, with additional guns and stowage

The Iron Warriors and the Imperial Fists recall the battle of the Cage of Iron differently: as the Iron Warriors tell it, the siege ended with Dorn staggering through the corpses of his sons, screaming challenges at a smiling Perturabo who never deigned to show his face.

Perhaps Perturarbo’s self satisfaction spared the loyalists from destruction, for the Iron Warriors were forced to abandon their murderous sport by the appearance of the Ultramarines – but it is the closest to satisfaction that many of them have felt in centuries since.

With thanks to Gonders for his mottled, Heresy era Iron Warriors, and 40kSteve for his up-gunned Land Raider. The other Iron Warriors are mine.