As we get closer to the new edition of Warhammer: The Horus Heresy, we’ve been uncovering brand new models – like yesterday’s Spartan Assault Tank – and delving into pivotal moments in the lore. The seeds of rebellion were laid by the Triumph at Ullanor and the lodges of Davin, but the full horror of the Heresy was only laid bare on the blasted battlefields of the Isstvan system.
Of all the betrayals in the Horus Heresy, no single act of treachery had such ramifications as the Drop Site Massacre. In one fell stroke, Warmaster Horus revealed the full scale of his revolt and smashed the combined strength of three loyalist Legions, even slaying – or so it first appeared – all three of their Primarchs.
When the Eisenstein brought word of Horus’ initial betrayal at Isstvan III to Rogal Dorn, the Primarch of the VII Legion was incensed, assembling a task force of seven combined Legions to bring the Traitor forces to justice. The Iron Hands, Salamanders, Raven Guard, Iron Warriors, Alpha Legion, Word Bearers, and Night Lords made full speed for the system, bringing nearly their full complement of Legionaries.
Little did the Loyalists among them know that more than half of their number had already sworn fealty to Horus, allegiances brokered long before the armada was launched. Of the hasty planning and execution of the Retribution Fleet, Graham McNeill – author of Fulgrim: Visions of Treachery – said this:“So many moments in the opening stages of the Heresy hung on a knife-edge, where they might, but for a series of seemingly small decisions, have gone the other way. But even before the doomed loyalists made their first drop, the Battle of Isstvan V was tragically inevitable, a moment carved in stone.”
The first wave of Loyalists landed in the Urgall Depression, finding the Traitors already dug in. Infuriated by the betrayal of Fulgrim, his closest friend, Ferrus Manus launched himself at the III Legion with 30 full companies of Iron Hands Terminators in tow. In turn, Vulkan and Corvus Corax advanced into battle alongside their own Legions, and soon tens of thousands of Astartes were clashing in brutal close combat.
Mauled by the Traitors’ ferocious defence, the Loyalists withdrew to regroup with the second wave of reinforcements now landing at their drop site. But these four Legions had other plans – once their brothers came into range, they opened fire without warning.
The Salamanders, Iron Hands, and Raven Guard were trapped and slaughtered. Vulkan and many of his finest officers were consumed in a nuclear bombardment launched by the Iron Warriors, while Corvus Corax – always more cautious than his brothers – almost escaped aboard a Thunderhawk Gunship, until it was shot down by the Traitor barrage. Locked in battle with Fulgrim, never once entertaining thoughts of retreat, Ferrus Manus could only watch as his brothers were laid low.
The Gorgon and the Phoenix fought with every fibre of their being, until Fulgrim finally ended the duel by disarming and decapitating his once-dear friend. In just over three hours, tens of thousands of Loyalist Space Marines had perished, the few survivors escaping aboard an Iron Hands battle barge that barely broke through the Traitor blockade.
Miraculously, both Vulkan and Corvus Corax had survived, though their Legions were broken – with up to 90% of their collective strength lying dead on Isstvan V.* Although remnants of all three Legions would go on to fight in many decisive engagements as the Shattered Legions, Horus had effectively removed a third of his most resilient foes from the board.
With the door to Terra now open, the Horus Heresy began in earnest. Join us again next week, as traitor fleets encroach upon the Sol System itself! You can find out which Legion you should support at the Horus Heresy website – make sure to let us know on our Facebook page whose colours you’ll be wearing.
* The damage would have long-term repercussions, with the Salamanders never again reaching Legion-strength, and Corax turning to ancient technology to rebuild his Space Marines.