Chaos Knights - Age of Degradation, M31-M41: Rise of the Idolators (ca. M31-M36) -  In the aftermath of the Horus Heresy, some amongst the Imperium believe the threat of the Chaos Knights to be diminished. However, such wishful thinking is quickly disproven. Even after the Traitors' defeat, Knight houses continue to turn upon the Imperium, swearing allegiance to powerful Chaos Lords or Daemon Princes, while the Dark Mechanicum delves deeper into their profane arts to pervert the ancient technology of the Throne Mechanicum. The Inquisition and later its Ordo Hereticus also become aware of the cults of technically-skilled Idolators who now serve the Fallen Noble households, and through whom corruption is spread to new Knight Worlds.Psychic Reign (ca.M34) - After learning of the existence of the Imperium of Man, the colossal alien cyborg known as the Cacodominus uses its potent psychic abilities to secure the services of seventeen wandering Dreadblades. Each of the Chaos Knights is charged with a different mission -- one is sent to find a sunless planet on which an ancient technological marvel is buried, another is tasked with rounding up and butchering every member of a rare alien species called the Axlo, while another is given the esoteric duty of protecting the time stream against the Tzeentchian Daemon Kairos Fateweaver. Meanwhile, the Cacodominus itself conquers hundreds of systems. When the creature is finally slain by the massed armies of the Legio Cybernetica and Black Templars, its dying psychic scream echoes across the galaxy, even distorting the guiding light of the Astronomican. The resulting backlash burnt out billions of Astropaths across the Imperium and resulted in millions of starships being lost and entire sub-sectors descending into barbarism. But the seventeen Dreadblades who serve it make no effort to seek revenge. Each had been commanded to pursue the individual task they had been given, come what may, and even the death of their liege is of little concern so long as the Cacodominus' will is eventually fulfilled.Wounded Prey - Whilst en route to the War Zone Kilda, the mass conveyance barge Dark Cloud becomes stranded in the Warp with a full lance of Imperial Knights of House Mortan waiting in its hangar. The Gellar Field that shields the disabled craft from the denizens of the Empyrean holds firm at first, until a series of massive objects impact with the ship's hull. The objects turn out to be Chaos Knights of House Khomentis. After clamping themselves to the barge, the Khomentis Knights begin blasting and cutting their way through its outer bulkheads to allow waves of Warp energy to flood inwards. Knowing that the Dark Cloud cannot survive long against such an assault, the Knights of House Mortan venture out onto the barge's exterior to do battle with their corrupted attackers. Though they fight bravely, the Mortan Knights are blasted to scrap by the Chaos Knights, and the souls of their pilots devoured by great flocks of predatory Daemons. With its last line of defence annihilated, the Dark Cloud is swiftly torn apart.The Spoils of Fate - In a single solar decade, nine Knight Worlds fall to the corruptions of Chaos, each launching a campaign of horror that sets dozens of Imperial planets ablaze. Though scattered across different sectors of the Imperium, these Iconoclast houses are found to have a connection that causes great vexation amongst the investigating Inquisitors. During the Great Crusade, Remembrancers had transcribed the ancient legends of each of these worlds, and all nine spoke of a figure that had appeared to their rulers during the Age of Strife. Known only as Manat, he had served as a vizier to powerful leaders of each of the Noble houses, and was reputed to have great powers of foresight. On some of these worlds he was seen as a villain, and on others a hero, but on all he had disappeared as suddenly as he had appeared, taking with him the head of the Noble household he served.Battle of Oumo - The Hatred of Krastellan, a Dreadblade and Fallen Knight of House Hawkshroud, descends upon the planet of Oumo and opens fire on the siege walls of the Agri-world's capital harvester city. The Oumoans, having been granted the sworn service and protection of Hawkshroud, are caught completely by surprise. After sending an astropathic distress signal to the nearby Forge World of Mezoa, they receive a reply from Tech- priest Dominus Telemetenos Vrae ordering them to cease all such communication. Vrae informs the Oumoans that it is a logical impossibility for a Hawkshroud Knight to be attacking them, and therefore firing upon this loyal Knight would be an act of treason against the Omnissiah. This message is disseminated across the planet, and the Oumoan regiments ordered to hold their fire. Without any form of resistance, the Hatred of Krastellan tears its way through the defences of Oumo's harvest cities one by one.The Kreen Scar - House Herpetrax launched a long and brutal campaign through the Kreen Worlds. Stretching over more than a hundred light years, this network of planetary systems served as a vital manufactorum hub in the galactic south of the Ultima Segmentum. Despite concerted defence efforts by the Astra Militarum and Adeptus Mechanicus, the Herpetrax advance progresses with staggering speed. The denizens of worlds that are conquered by the Iconoclast house are enslaved, and are put to work excavating the foundations beneath the towering hive cities in which they live. Billions die in the process, crushed beneath slabs of ferrocrete, buried in catastrophic cave-ins or simply collapsing from starvation and exhaustion. But on several of these planets the Fallen Noble overlords uncover what they are searching for. The long-forgotten remains of ancient Long March generation ships are prised from the earth -- the remnants of failed Human colonies from the Dark Age of Technology. These precious cargoes are taken back to the Fallen Knight World of Jedathra, while the surviving slave populations are exterminated by massed orbital bombardments. Over the course of a generation, the belt of Imperial manufactorum worlds is transformed into a ruined and lifeless stretch known as the "Kreen Scar."Price of Betrayal (ca. M36) - Word spreads across the Imperium of the death of Goge Vandire, the tyrannical Ecclesiarch and High Lord of Terra. Those who are still loyal to Vandire begin exacting their revenge upon the Imperium on multiple fronts, attacking Shrine Worlds and tearing down monuments to Imperial saints. None are more fervent in this regard than Hope’s Shroud. The Freeblade Knight and its pilot -- whose identity was known only to Vandire himself -- had sworn to serve the Ecclesiarch in life and death, and so set about taking revenge on those who had betrayed him. The first targets of the excommunicant Knight's wrath are the Sisters of the Order of the Ebon Chalice, for it was their Matriarch Alicia Dominica that slew Vandire. After a series of escalating battles, Hope's Shroud succeeds in claiming the head of the Order's Canoness Superior. Over the next two millennia, the fanatical Knight claims the heads of other Canonesses Superior, one for each of the six Matriarchs that turned on Vandire. The skulls are hung as trophies from the increasingly warped armour of Hope's Shroud.Dark Siege - Lances from five Fallen houses besiege a Webway portal inside a hollowed out, wandering moon. The portal leads directly to Seyahmva'ar, an outer district of Commorragh ruled over by the Drukhari's Kabal Opaque. Rather than helping to repel the Chaos Knights, Commorragh's Supreme Overlord Asdrubael Vect instead dislocated Seyahmva'ar from the city proper, leaving the Kabal Opaque to be torn apart.Fall of Graggen Keep - On the Death World of Friggenswald, Renegade Astra Militarum infantry regiments lay siege to the towering fortress known as Graggen Keep. Though the keep is defended by only a handful of soldiers, two factors prevent the attackers from achieving a swift victory. The sludgy acidic river surrounding the fortress instantly dissolves those Renegades who attempt to launch an assault. Furthermore, from its position inside the walls, the Freeblade Knight Unflinching Steel fires a ceaseless hail of Rapid-Fire Battle Cannon shells into the ranks of the encroaching army. The Knight had once been a member of House Lucaris, but had abandoned his household when they turned Traitor, and had fought valiantly for the Imperium ever since. Yet the initial victories of the defenders only delayed the inevitable. The Chaos Knights of House Lucaris arrived on Friggenswald and marched upon Graggen Keep. Having served their purpose of holding Unflinching Steel in place, the Renegades withdrww out of firing range while the Lucaris Knights wade through the acid flows surrounding the fortress. A trio of Knights Rampager made short work of the fortress walls, allowing the remaining war engines to pour through the breach and annihilate the defenders. Unflinching Steel was brought down and dismembered by the members of its former household, but was not destroyed. Instead, its battered and mutilated chassis was taken back to the Fallen Knight World of Morda Prime to face judgement.Tower of Scintillus - The High King of Barragon, a Loyalist Knightly household, was abducted by a sorcerous Chaos Cult of Tzeentch. Those Knights that served the king set out to find their liege, eventually tracking his location to the world of Scintillus. But upon entering the reality-bending tower in which the king was imprisoned, each Knight was transformed into a crystalline statue, lifeless and utterly immobile. Only when another Knight entered the tower did the statues come to life and fire upon their erstwhile compatriots.Battle of Tellerax Prime - The Dreadblade Litany of Destruction fought alongside Heretic Astartes of the Iron Warriors Legion during the invasion of the world of Tellerax Prime. Telleraxi infantry regiments establish bristling defensive lines across the planet's sump fields and around key hive cities, but even with the support of an armoured detachment of the Ultramarines 3rd Company they are unable to repel the influx of Chaos warriors. A grinding siege ensues. The Iron Warriors pin their foes in place with ceaseless orbital and land-based bombardments, allowing Litany of Destruction to rove freely, annihilating any Imperial forces unfortunate enough to be caught in its path. Only when the Knight Paladin Ever-Stalwart arrives to aid the besieged forces does the state of battle shift. Amidst the shattered remains of Hive Permillion, the Dreadblade and the Imperial Knight engage in a titanic duel. After an hour of traded blows, the Litany of Destruction gains the upper hand, striking down its Loyalist opponent and readying the killing strike. But the Chaos Knight is denied its victory when a column of Predator tanks fire upon its flank. The Litany tears its way through the armoured column and retreats under the covering fire of the encroaching Iron Warriors, enraged at the Ultramarines for interfering with its rightful kill.The 13th Black Crusade (ca. 999.M41) - Iconoclast households, Infernal households and Dreadblades from across the galaxy flock to the banner of Abaddon the Despoiler, the Warmaster of Chaos, as he launches his 13th Black Crusade. Dread lances march on multiple fronts. In the Mackan System, Chaos Knights of House Khomentis hunt the Howling Griffons' 5th Company, using the mutants of the Stigmatus Covenant to flush the Space Marines from cover. On Belismar, the Dreadblade Bleak Dawn single-handedly wipes out the unsupported Narsine 18th Infantry, filling the Gracien Trench with their corpses. Meanwhile, on Macharia, Chaos Knights of House Vextrix, House Iattol, House Mesmr and House Lucaris battle alongside various warbands of Heretic Astartes to lay waste to the militarised hive cities. Throughout the crusade, many Knights pledge fealty to Abaddon for the first time, whereas others settle blood oaths against the Imperium that had stood for millennia.Slaughter at Armageddon (ca. 999.M41) - In the wake of massive Warp upheavals follwoing the fall of Cadia to the 13th Black Crusade, the first Khornate daemons spill onto the surface of Armageddon, attacking Orks and Imperial soldiers without discrimination. Shortly after, the Dreadblade Incarnate Slaughter, which accompanied the daemonic forces, rises from the gore of the slain.