The Civil War of the Horus Heresy marks humanity’s history as it’s single bloodiest campaign. Once noble Brothers and Fathers rent the galaxy in twain in the name of betrayal, false gods and hubristic ambition. No other conflict would emulate the atrocities and warcrimes committed during the 31st Millennium,
And one battle above all epitomised the conniving and malevolence of the Traitor Rebellion. For today we shall Elucidate a warzone which sundered three full-strength legions and would be remembered within the greatest infamy in Imperial Records. This is the tale of the Battle of Istvaan 5: the Dropsite Massacre.
Horus Lupercal: Warmaster of the Imperium and Primarch of the 16th Legion denounced the rule of the Master of Mankind and began to tread the path of treachery. Having already culled his own Legion and those of his complicit brethren: Primarchs Fulgrim, Angron and Mortarion,
The Lupercal’s atrocity of Istvaan 3 had marked the first great victory in his campaign to usurp the Emperor. Despite his successful plot to cleanse his armies of Loyalists, the Traitor Legions had endured losses and cost in excess of their projections
Due to the stubborn defiance of heroes such as Saul Tarvitz, Nathaniel Garro, Tarik Torgaddon and Garviel Loken. Four Legions could never hope to conquer the Imperium, and so it was that the Warmaster devised plans to rally the rest of his Brothers to the fold.
Knowing in his heart that the valiant Primarchs Lion El’Jonson, Sanguinius and Roboute Guilliman would never abandon their genefather; the Warmaster dispatched the vast contingents of the Dark Angels, Blood Angels and Ultramarines far from the conflicts of Istvaan.
Dispatching his brother Fulgrim: Primarch of the Emperor’s Children to convince his most cherished brother Ferrus Manus to join their cause, the Gorgon of Medusa would be among the mightiest leaders of the rebellion should he pledge his allegiance. Meeting with the Gorgon within his Anvilarium aboard his flagship: Fist of Iron,
The Phoenician attempted to sway the Iron Hands to join him in overthrowing the Master of Mankind. Furious at such a blatant act of duplicity, the Gorgon refused to aid such madness and for his defiance let free the wroth of Fulgrim.
Destroying the weapon he had once crafted as a gift of brotherly love: Fireblade with his hands of Necrodermis, the resulting explosion of the weapon proved sufficient to give Fulgrim the upper-hand. Already manipulated by the Daemon of the Laer Blade,
The Phoenician incapacitated the Primarch of the Iron 10th and ordered his men to murder his Morlock Honour Guard. Awakening to find all but his 1st Captain: Gabriel Santor deceased and several vessels of his fleet crippled, the Gorgon resolved to lead the charge of the Emperor’s retribution fleet.
As word reached the Master of Mankind of the Betrayal of Istvaan 3, delivered by the surviving Loyal Battle Captain of the Death Guard: Nathaniel Garro; further reports from Ferrus Manus of Fulgrim’s betrayal galvanised the Loyalist hunger for vengeance.
Rogal Dorn: Magister Militum of the Emperor commanded Eight Legions including a contingent of his own men to crush the rebellion before it had a chance to fester, with three Primarchs at the speartip of their assault.
Vulkan: the Drakelord of the Salamanders and Corvus Corax: Ravenlord of the Raven Guard pledged to fight alongside the Gorgon and his Iron Tenth; whilst meanwhile Fulgrim and the Dark Mechanicum prepared the world of Istvaan 5 for the impending assault.
Aided further by a second wave of Legionary assault by the Iron Warriors, Night Lords, Word Bearers and Alpha Legion; any hope of victory for the Traitors could not be achieved when set against such overwhelming firepower. An assumption which would cost the Loyalists dearly…
Although a large contingent of the Imperial Fists had been dispatched to reinforce the Loyalist invasion, turbulent Warp-Storms impeded the Sons of Dorn from entering the fray. Despite being diminished to the strength of seven Legion,
The Retribution Fleet of the Emperor under supreme command of the Gorgon would prove more than sufficient in quelling the Traitor Rebellion. With all haste the Iron Hands, Salamanders and Raven Guard arrived within the Istvaan-system, unaware of the machinations of the Ruinous Powers expediting their traversal through the Warp to reach their target.
The Traitors has mustered upon the world of Istvaan 5, yet reports of the desolate husk which had been it’s sister planet: Istvaan 3 marked the blood already spilled within this accursed system of space.
No traitor fleet was present only a myriad horde of foes dug deep into the soil of the Urgall Depression of Istvaan 5, standards of the 3rd and 16th Legion proudly goading the Loyalists to attempt an land-fall. Already incensed from his encounter with the Phoenician,
Ferrus Manus wasted no time in ordering his forces to combat the Traitors. Their enemy was vulnerable, their forces still wounded from the purge of their own Legions, now was the time to strike. Yet unbeknownst to the Loyalists a compact between the Traitors and second assault of the Emperor’s wroth had been made.
Lorgar Aurelian aboard his flagship: the Fidelitas Lex enacted the next masterstroke of his plot to corrupt the Imperium to the thrall of chaos. Meeting with the Primarchs Perturabo, Konrad Curze and Alpharius Omegon, the delegations listened to the honeyed words of the Urizen.
Promising a new era under the rulership of a True Emperor imbued with the favour of the Dark Gods, Lorgar proclaimed that should they side with the Warmaster each of their Legions would be rewarded in kind. Declaring the phrase: ‘Death to the False Emperor’,
The phrase uttered by the First Captain of the Night Lords Legion: Jago Sevatarion resounds to this day as the rallying warcry of murderers, zealots, degenerates and Chaos filth across the stars. Whilst the second wave of reinforcements hurtled towards the Istvaan system, unified in purpose the Loyalists began their assault.
In the opening salvo the Loyalists bombarded the positions of Horus’ rebels, the Emperor’s wroth made manifest as Emperor’s Children, World Eaters, Death Guard and Sons of Horus sheltered as best they could from the orbital bombardment: The flames of war subsided and with the Traitors reeling from the bombardment,
The Gorgon unleashed the Legions of the Emperor. Three noble sons of the Emperor at the head of their vast Legions took to the field, Vulkan combatting the Traitor’s left flank, Corax striking the right flank and the Gorgon pushing to the center.
Both sides of the fray were equal in size, for whilst the Traitor Legions had incurred losses from Istvaan, the Salamanders and Raven Guard had a reputation as among the smaller forces of the Legionnes Astartes. The Iron Hands formed the bulk of the assault,
Veterans of hundreds of compliances throughout the stars and regarded as among the greatest Legion even by the Warmaster himself. Their stubborn taskmaster epitomising the Emperor’s martial skill brought to bear, Ferrus Manus saw to the slaughter of thousands of Traitor Astartes mere minutes following land-fall.
Progress was slow, yet the Loyalists could not relent in their aggression knowing that reinforcements were imminent in supporting their attack. The Urgall Depression ran thick with both Loyalist and Traitor blood, already the battle proved to be among the most bloody engagements seen since the Great Crusade.
Loyal War Machines of Legio Atarus alongside the Iron Tenth combated the Legio Mortis of the Traitors, supported by armoured divisions of the Sons of Horus and World Eaters. Wading through the thickest of fighting the Loyalists Primarchs carved swathes through the enemy lines knowing that soon this bloody work would be over.
For today the Primarchs of the Imperium would fall, yet none among the Traitor ranks. The Traitor Primarchs took to the field, butchering any within their path. Angron: Primarch of the World Eaters sated the cravings of his Chainaxes Gorechild and Gorefather
Whilst Fulgrim’s laughed with glee as the keen edge of the Laer Blade tore through the ranks of the Iron Hands. Mortarion harvested the lives of the Loyalists with arching sweeps of his Warscythe: Silence yet no sight could be seen of the Warmaster.
Watching the battle unfold from afar, the Lupercal smiled at the sight of the second wave of the Loyalist advance. Drop Pods descended from the heavens and the sky darkened as tens of thousand of shadows cast a pall over the Urgall Depression.
A cheer arose from the Loyalists as Iron Warriors, Night Lords, Word Bearers and Alpha Legionaries took to the field. Calling for medical aid from their newly arrived kin, the Salamanders and Raven Guard regrouped yet received no confirmation of their calls as the fresh Astartes looked on in grim silence.
The Traitors retreated from the battle and with victory sealed in the name of the Emperor the Gorgon charged after the Phoenicians’ withdrawing forces. Separated from his allies, Ferrus Manus watched in horror as the Iron Warriors claimed the high-ground of the depression and turned their guns of his men. All around the reinforcements encircled,
Training their sights on Astartes clad in green, black and chrome. Whilst the Night Lords took up defensive positions with aid from the Word Bearers, the Iron Warriors and Alpha Legion would act as the hammer driving the Loyalists to their respective anvil.
Isolated from the Gorgon, Corvus Corax and Vulkan ordered their men to fall back, a lone flare erupted from the fortress of the Warmaster. Volleys of Bolter fire fell upon the Loyalists trapped within the Urgall Depression, killing hundreds of Astartes before the first magazines of their guns had been ejected.
Returning to the fray the bloodied Traitor Forces from the first wave joined forces with the newly arrived legions and cut down the Iron Hands. 1st Captain Kor Phaeron, 1st Chaplain Erebus and Lorgar Aurelian looked on with smug satisfaction at the Massacre unfolding
As a smile came close to forming on the Urizen’s lips. Clutching the weapon made for him by the Gorgon: Illuminarum, Lorgar’s mind felt a pang of doubt as he watched the Primarch of the Iron 10th struggle for his life.
Reassured by his adoptive foster-father: Kor Phaeron, Lorgar ordered his Legion to commit to the fray. Corax and Vulkan could not come to a consensus of how to salvage their armies, the Lord of Drakes suggesting a tactical withdrawal followed by fortifying their positions whilst the Ravenlord argued a full-scale escape effort.
Such arguments would be ended by an artillery strike upon their position, and though the Ravenlord survived the blast radius yet found no trace of Vulkan. The Primarch of the Salamanders was missing, the Ravenlord had ordered his men to retreat and the Iron Tenth were fully surrounded.
All hope of victory in the name of the Emperor was lost. Dozens of Thousands of Loyalists had fallen with the Iron Tenth receiving the most casualties. The rage of Ferrus Manus was legendary among the Imperium, for he has not achieved the title of ‘Gorgon’ for his compassionate disposition nor fair looks.
Yet never before had Ferrus felt such betrayal, such loss of his men or flagrant treachery. This sin committed by the Warmaster and his allies was unforgivable and no matter how slim a chance, the Gorgon refused to die without claiming the head of he who had wronged him. Fulgrim took to the field,
Reveling in the slaughter of his once-cherished sons armies and the whispers of the Laer Blade promising glory and satisfaction. The two demi-gods of war met in battle, their eyes locking as the merciless cruelty around them reached new heights of suffering. For a moment the Phoenician faltered,
The eyes of the Gorgon had never once been fueled by such hatred and never directed at his own gaze. Knowing that all chance for reconciliation lay dead, only through battle would either of them be freed from their bonds of broken brotherhood. Morlocks and Pheonix Guard clashes,
Their former campaigns as allies torn asunder and little more than fuel for thirst for vengeance. Wielding the reforged weapon: Fireblade, Ferrus had pledged to end the life of his fallen Brother with the gift he had once made in the name of fraternity. Fulgrim carried his own craft: Forgebreaker,
Retrieved from Ferrus during their previous encounter had been carried into every battle the Gorgon had waged since its creation. Today a Primarch must die and as the two clashed, the weapons once pledged to one-another shook the earth as they impacted.
As each traded terrible blows and further stoked the fires of anger within their hearts, until the Gorgon drew Fireblade within moments of slaying the Phoenician. Yet as Fulgrim let go of Forgebreaker and drew the Blade of the Laer he felt unnatural power course through his body. Reeling from this surprise renewal of strength,
Ferrus blocked each strike from the Xenos relic until it’s tip pierced his breastplate. Falling to his knees, the Gorgon felt Fireblade slip from his grasp and looked up in horror at the transformed visage of his Brother.
In a moment of clarity, Fulgrim realised the mistake he had made when drawing the blade from it’s sheath and fought to release it from his grip. Unable to unclasp his fingers from the weapon,
The Phoenician struggled with the knowledge that he had fallen deep into the depths of corruption as Ferrus reached for Fireblade. As fire wreathed the Gorgon’s weapon the Laer Blade moved as if of it’s own volition,
It’s unnaturally sharp edge cleaving through the neck of Ferrus Manus as Fulgrim desperately tried to pull the blow. The Gorgon was dead, and as the Phoenician cradled his Brother’s severed head in his arms he knew that his own soul was forfeit to the whims of malevolent thirsting gods.
The Raven Guard has pulled back from the killing field yet would not be allowed to escape unscathed. The Word Bearers lead by their zealous Primarch: Lorgar Aurelian could not allow the Ravenlord to take flight
And with his trusted lieutenants Kor Phaeron and Erebus at his side attempted to clip the wings of the Raven Guard. The Gal Vorbak: twisted daemon hosts of the 17th attacked the Liberator en-masse yet despite their warp-twisted forms could not hope to best of a Primarch.
Unwilling to watch his most pious sons perish the Rainmaker intervened, his anger stoked and blood risen. Of all the sons of the Emperor Lorgar Aurelian was by far the weakest in martial skill,
Yet it was a bitter irony that his weapon once gifted by the Lord of the Iron 10th cut down loyalist Astartes as it’s maker lay cold and dead within the Urgall Depression.
Corpses of Ravens and Zealots piled high as the two Primarchs waded through the hordes of their enemies and soon the two came to blows. The Urizen had no hope of winning a duel with the Ravenlord,
The two sons of the Emperor had never been close and were almost strangers estranged for over two centuries since last they spoke. Releasing his long repressed psychic power with careless abandon, energy wreathed Lorgar as he demanded Corvus face him in battle.
Crozius and Claw collided, the Urizen parrying vicious blows whilst the Ravenlord cleaved at the Rainmaker’s neck. Cutting a gauge from Lorgar’s face, the wound inflicted by Corvus was destined never to heal and forever mark the Urizen’s visage. Impaling Lorgar through the chest with his Lightning Claws
Corax resisted the pain of the Urizen desperately crashed his head against his features smashing the bones of his face. Tearing free his claws moments before achieving the killing blow a sadistic mirror of the Liberator stepped in. Konrad Curze: the Night Haunter of Nostramo smiled as his own claws scraped against the Raven’s,
A grim promise of murder etched on his features. Seizing Corax’s wrist Curze attempted to prevent the Ravenlord from escaping, yet as he berated the Bearer of the Word Corax took flight. Warning Lorgar that should he fail again he would not save him,
The Night Haunter looked upon the twisted forms of the Gal Vorbak with disgust. Commenting that his Legion and own character were malformed with corruption, even the Monster of Nostramo felt disgust at the sight of the Sons of Lorgar.
Yet whilst the rewards of victory tasted bitter to many of the Traitors, Loyalists lingered among the ashes of war, for now began the hunt for the survivors of the Massacre. Fighting until the bitter end,
The vast proportion of the remaining survivors of the Massacre fought tooth and nail to slow the Warmaster’s his victory. Tens of Thousands perished as the advance of Angron, Mortarion and the Imperator-class Titan: Dies Irae butchered and maimed anything in their path.
Taking to the field, Horus Lupercal lead his Justaerin Terminators to mop-up any remaining holdouts of the Loyalist forces, his victory assured with two Primarchs slain and one broken and bloody. The Iron Warriors destroyed the Loyalists drop-ships, preventing escape to those within reach of salvation from the heinous butchery
Whilst Night Lords, Word Bearers and Alpha Legionaries corralled the Loyalists into killing zones. The Raven Guard had suffered the least casualties and as experts of hit-and-run proved the most adept at procuring vessels for their escape.
Compassionate to a fault the Salamanders though bereft of their gene-sire assisted the Iron Hands in escaping the slaughter as the stubborn sons of Medusa begrudgingly resolved to avenge their gene-father another day. Meanwhile Vulkan and a contingent of his men fought on,
Battered and bruised the stalwart warriors of Nocturne proved their renown as soldiers forged of mighty constitution. Unwilling to endure further casualties from the hammers of the anvils of war, the Iron Warriors ordered a tactical nuclear warhead to be fired upon the Lord of Drake’s position.
Atomising the Primarch of the 18th and his men the Traitors had sealed their victory with excessive firepower, cunning and cowardice. 200,000 Astartes had perished, a son of the Emperor had been slain and three Legions loyal to the Emperor had been annihilated. The Master of Mankind’s dream of a united galaxy was dead,
The Warmaster of the Imperium had secured a supreme advantage in the first stages of the Great Civil War and the defenders of Humanity remained scattered across the void. Warships of the Loyalists crashed unto the surface, their detonations creating vast craters and scars as they tumbled from orbit.
Word Eaters flensed their kills of flesh, constructing Ossuary-cairns from the skulls of the fallen whilst Word Bearers conducted fell rituals using grievously wounded loyalists. Loyalists turned on their allies as madness and grief eroded their stoic countenance as the War machines of the Traitor Legios rooted out makeshift holdouts and rally points.
Retrieving tens of thousands of Progenoid glands from the dead, the Traitors harvested these precious organs of the Astartes for their own dark purpose Yet even in this darkest of days glimmers of hope remained. Vulkan of the Salamanders against all odds had somehow survived the engagement,
Though with his discovery by the Night Haunter of Nostramo soon languish as a prisoner of war. Small bands of resilient Space Marines of the now Shattered Legions formed bands of war-forged brotherhood to harry the Warmaster’s forces for years to come.
The Fleet in orbit of Istvaan though outmatched in firepower lasted far longer than the engagement on the surface of the planet, facilitating escape attempts and destroying several traitor voidcraft in the hours following the conclusion of the ground war.
For twenty solar days the Loyalists had bitterly fought to preserve the honour of their legions with the Ravenlord leading the survivors as they sought a means to escape the wroth of the Traitors that remained.
World Eaters, Sons of Horus and Iron Warriors scoured the ruin of Istvaan 5 for prey yet the Ravenlord refused to allow the extermination of his charges. Countering the purge of the Iron Warriors for solar weeks, after gathering much needed intel on their surroundings the Deliverer proved worthy of his title.
For ninety eight solar days the Ravenlord orchestrated ambushes against the Traitors yet now a chance for escape presented itself within the Gular Salt Plains. Lead by Captain Branne Nev of the Raven Guard, drop-ship reinforcements from Deliverance had to come their master’s aid
And with haste extracted as many survivors as possible from the onslaught of the Red Angel: Angron. Watching the futile blood-crazed screams of the World Eaters as they departed from the surface, Corax demanded answers pertaining to how Branne had come to Istvaan.
Convinced by the Praefector of the Therion Cohort: Marcus Valerius’ prophetic visions of ruin, the mortal of the 19th Legion’s expeditionary fleet though largely forgotten by history had proven crucial in preserving the life and legacy of the Liberator. The voyage of fifty thousand light years timely in it’s arrival,
Many valiant souls would be spared the blades and axes of the butchers of Nuceria. Whether these visions were imparted by the grace of the Emperor is unknown, yet the Shattered Legions for all their losses had been saved. The Traitor Legions had galvanized into a force capable of sundering the Imperium
And following the Battle of Istvaan 5 had come close to extinguishing three entire Loyalist Legions. The Loyalist were scattered, several Legions were broken and as the denizens of the Warp continued to entrap and harry Warp-travel
It would take 133 Solar Days for the survivors of Istvaan 5 to return to the sanctuary of Holy Terra. Two Loyal Sons of the Primarchs had perished and the remnants of the Shattered Legions were largely leaderless and diminished to only a few thousand souls.
No battle waged in the name of the Imperium would ever eclipse the losses of the Astartes incurred from the Dropsite Massacre, for such an engagement is less attributed as a battle but rather a slaughter.
The Warmaster’s gambit had paid off and with his victory achieved the Lupercal rallied his remaining Traitor brethren to his cause. Forming a conclave of the Primarchs Horus now allied with Perturabo of the Iron Warriors,
Konrad Curze of the Night Lords, Alpharius Omegon of the Alpha Legion and even Magnus the Red of the Thousand Sons set his gaze upon the void. Nine Legions stood at his banner and it was not time to take their first steps to conquer Holy Terra.
The forces of the 3rd, 12th, 14th and 16th Legions would rendezvous at Mars to liaise with the Dark Mechanicum to aid the Schism of Mars in order to resupply and bolster their armaments.
The Night Lords departed to the planet of Tsagualsa in order to delay the Dark Angels from countering the Warmaster’s forces whilst the Iron Warriors would confront their nemesis: the Imperial Fists stranded within the Phaal system.
The Death Guard busied themselves with a mission to recruit the White Scars to the fold of the Imperium and the Alpha Legion had infiltrated the ranks of the Raven Guard and were also tasked with harrying the Space Wolves Legion.
Whilst the traitor Legions pilfered the armaments and wargear from the corpses of Istvaan 5, small Blackshield warbands amassed within the void to combat the Warmaster’s fleets. Unable to confront the Traitors head-on, these bands of orphaned Astartes regardless of their scale continued to harry the Warmaster’s supply lines and patrols.
The heroism of such venerable Legions bolstered by grievous losses the warriors of the Iron Hands, Salamanders and Raven Guard refused to surrender in the face of overwhelming odds. Surviving to the days of the 41st Millennium as valiant champions of the Adeptus Astartes,
Their service though among the most devastated regardless endures to this day. Never again would the Imperium suffer such catastrophic losses to such a one-sided encounter, yet news of the Civil War of the Horus Heresy still remained unknown to many forces of the
Imperium loyal to the Emperor and they would not be spared further deception… This has been a tale of the Great Imperium of Man. Read by the Remembrancer. The losses incurred by the Loyalists of Istvaan 5 would never again be suffered by the Imperium.
Many trials and tribulations lay ahead for Humanity following this grievous wound, yet from the bleakest of nightmares shine the brightest of souls. Remember the fallen of Istvaan 5 for their sacrifice was not made in vain, our Imperium stands to this day emboldened by the hatred of betrayers and murderers.
For self sacrifice is never futile so long as it is cherished by those who find salvation from it’s deeds, so never forget those who give life and limb to enable your well-being and prosperity.
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