The '''{{PAGENAME}}''' was a major battle fought by the [[Imperium]], sometime after the [[Thirteenth Black Crusade]].{{Fn|1}}

The invasion began after the creation of the [[Great Rift]] during the [[Thirteenth Black Crusade]], when the [[Chaos God]] [[Tzeentch]] grew jealous of its Brother [[Nurgle]]'s newly acquired domain of the [[Scourge Stars]]. While Tzeentch began to undermine Nurgle's control of the Scourge Stars, the Chaos God also wished to corrupt a realm of space for itself and selected the [[Imperium]]'s [[Stygius Sector]] to be its domain. This was due to the fact that Stygius Sector was still awash with [[Warp Storm]]s created by the Great Rift's opening and as a result, the light of the [[Astronomicon]] could no longer be seen there; all of which made the Sector an inviting target for the Chaos God's forces.{{Fn|1}}

Just as the Crusade began to fall to Tzeentch's might, a large strike force from the [[Craftworld]] [[Ulthwe]] arrived in the Sector without warning and began to push back the Chaos God's forces. The [[Eldar]] did not arrive to aid the Crusade against the forces of [[Chaos]] though. Instead, the Craftworld's [[Seer Council]] contacted the Crusade's commanders and told them they could not save the Stygius Sector and staying there would not aid the Imperium. Indeed, the Seer Council claimed the visions they had received showed only the Crusade's destruction if they stayed and warned that Magnus knew this as well. Despite the mistrust the Imperium had for the Eldar, the Crusade's commanders agreed to retreat and evacuated what forces they could, as Ulthwe's strike force acted as a rearguard against Tzeentch's hordes. Eventually though, the Crusade and Eldar were both forced to retreat and the Stygius Sector became the first of the domains Tzeentch planned on claiming for itself.{{Fn|1}}

As Imperial forces withdrew from the Stygius Sector the [[Iron Hands]] refused to retreat and instead gathered on [[Mordian]], itself under siege from Chaos forces. Alongside a mere dozen or so [[Regiment]]s of the [[Mordian Iron Guard]], the Iron Hands sought to reforge themselves and purge their weakness displayed earlier in the campaign. During the Siege the Iron Hands were joined by allies enraged by the defeatism of the Imperial forces, among them the [[Brazen Claws]], [[Fire Lords]], [[Silver Skulls]], [[Sons of Medusa]], and [[Iron Lords]] in what became known as the Iron Crusade. They arrived on Mordian to find the planet terrorized by a [[Night Lords]] warband under [[Ahrak Deathshriek]] and his [[Chaos Raptor|Raptor]] hordes. Deathshriek planned to use the terror to power a ritual that would plunge the entire world into the Warp.{{Fn|2}}

prophecy to the detriment of Mankind. [[Kardan Stronos]] in particular came to believe that had the Imperial forces held their ground, four of the six systems could have been held for acceptable cost. This, he now revised to two. The warp corridor between Mordian and Cypra Mundi had proven resistant to the grasp of the [[Noctis Aeterna]] offering a ready supply of materiel from the forge world, but this alone would not be enough. The bounteous worlds of the neighboring [[Khravos System]] would have to have to be secured – a campaign whose outcomes fell well within acceptable parameters. Thus ignoring Eldar prophecies insisting doom, the Iron Council unleashed a second phase of the campaign, with a plan to scour the surviving worlds of the Mordian System and wresting the refineries and shipyards of Kharvos from Chaos. As of now, the battle continues.{{Fn|2}}

During the war, the [[Space Wolves]] [[Wolf Lord]] of the [[Ironwolves]], [[Vorek Gnarlfist]], was killed by the forces of the Thousand Sons. His successor [[Torval Wyrdbane]] of the [[Duskwolves]] has launched a bloody campaign of vengeance against the sons of Magnus. Dubbed the Shadow Wolf, Wyrdbane has provided hope to the Imperium's besieged citizens amidst the ever-swelling tide of misery. He has taken the heads of no fewer than four [[Sorcerer]]s, most notably [[Kayesh Vrall]] on [[Kalimar]].{{Fn|3}}

====Imperial-Eldar{{Fn|1}}====

On [[Mordian]]

*[[Conjurers of Fear]] — [[Chaos Cult]]

*{{Endn|1}}: [[Warhammer 40,000 8th Edition Rulebook]], pgs. 164–165 — ''War Zone: Stygius''

*{{Endn|2}}: [[Codex Supplement: Iron Hands (8th Edition)]] pgs. 32-33