They have waged multiple barbaric campaigns against the Imperium, butchering those who fight in the Emperor's name in all corners of the galaxy, and over the course of ten thousand Terran years have reaped a toll of carnage too high for any single scriptorum to record.
They have been called the "House of Serpents," the "Fanged Knights" and many other names, but whatever they are called, the Knights of Lucaris are always synonymous with terror.
Morda Prime -- the homeworld of House Lucaris -- is shrouded in perpetually raging storms. It is from beneath this lightning-scape that the Lucaris Knights launch their dread campaigns, striking out at Imperial holdings across the galaxy.
During the Great Crusade, the Luna Wolves Legion arrived at the tempest-wreathed world of Morda Prime, where they found the Knights of House Lucaris. The Nobles of the household immediately swore allegiance to Horus, for in the Warmaster they saw manifested their own tenets of virtue through strength, and mercy through dominance.
They answered his calls to battle without question, employing thunderous assaults to crush all who dared oppose their liege's will. Even when he turned to Chaos, the Knights of Morda Prime held true to their vows of service.
When the Warmaster was killed at the Siege of Terra, House Lucaris swore an oath of undying enmity against the Emperor. They also forswore their allegiance to the Black Legion, successor of the Sons of Horus, which had abandoned its fallen Primarch.
In the millennia since, House Lucaris has waged apocalyptic wars against both the Imperium and the Heretic Astartes, though in more recent centuries there have been accounts of them marching alongside the Black Legion once more.
Fall of Graggen Keep
On the Death World of Friggenswald, Renegade Astra Militarum infantry regiments laid siege to the towering fortress known as Graggen Keep. Though the keep was defended by only a handful of soldiers, two factors prevented the attackers from achieving a swift victory.
The sludgy acidic river surrounding the fortress instantly dissolved those Renegades who attempted to launch an assault. Furthermore, from its position inside the walls, the Freeblade Knight Unflinching Steel fired 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 Morda Prime to face judgement.
Battle of Vigrid
The Great Game for supremacy between the Chaos Gods eventually spilled into realspace, leading to a series of hellish conflicts across the worlds deep in the Imperium Nihilus. Greatest of these was the Battle of Vigrid, where vast armies of each of the Ruinous Powers engaged in a sprawling combat.
Eventually a contest of champions was proposed whereby the Greater Daemons of each god would engage in single combat. The nightmarish war cries from this contest echoed through the Warp, liquefying the minds of psykers for light years in every direction -- and drawing the attention of House Lucaris.
Four Lucaris Knights were sent to engage in the Vigrid tourney, to prove the might of the Iconoclast house. Those Knights that duelled the champions of Khorne, Nurgle and Slaanesh were all victorious, but it soon became apparent that they had been bestowed with a portion of Tzeentch's fate-bending power.
These three Chaos Knights managed to escape the battle zone before the daemonic armies descended into open war once more, carrying with them the sorcerous gifts of the Changer of Ways.
- Iron Malice - This Knight Desecrator is piloted by Lord Obidar who claimed the Stratus Keep on Morda Prime. When Iron Malice descends from its mountainous abode to gather warriors for another campaign, a nimbus of crackling electricity clings to its hulking frame. In the thick of battle, rivulets of lightning continually burst from its vents and spark around its joints, growing more anarchic as the Chaos Knight's fury increases.
- Bringer of Extinctions - Bringer of Extinctions is the Knight Rampager piloted by the Fallen Noble Ifanor.
- Thunderhead - Thunderhead is the Knight Despoiler piloted by Lady Elsyr.
- Lord Obidar - With his Knight Desecrator known as Iron Malice, Lord Obidar has earned a fell reputation amongst House Lucaris. The dread campaigns he has launched against Imperial worlds are typified by their speed and ferocity. When besieging a planet, the Fallen Noble typically directs his onslaughts against spaceports and transportation hubs, ensuring that his victims have no means of retreat. However, he rarely targets astropathic relays, as he welcomes any enemy reinforcements that would dare face him. Obidar claimed the Stratus Keep on Morda Prime after crushing the head of its previous owner in a duel. Sitting atop a vast mountain range, the keep is perpetually engulfed by storm clouds.
- Ifanor - Since bonding with his Knight Bringer of Extinction, Ifanor has waged a merciless war against the Loyalist Knights of House Krast.
- Lady Elsyr - The impetuous Lady Elsyr and her Knight Despoiler, Thunderhead, are often the first of their lance to engage the enemy.
House Lucaris' Knights sport black, red and yellow house colours.
The arms of House Lucaris are a sinuous, red serpent with a lashing tongue.
- Codex: Chaos Knights (8th Edition), pp. 14-15, 29, 32-33