The Night Lords were originally the VIIIth Legion of Space Marines created during the First Founding and became one of the 9 Traitor Legions of Chaos Space Marines that betrayed the Emperor of Mankind during the Horus Heresy of the 31st Millennium
Konrad Curze, better known as Night Haunter, the name he preferred, was one of the 20 superhuman Primarchs created by the Emperor of Mankind in the late 30th Millennium and was the commander of the Traitor Legion of Chaos Space Marines known as the Night Lords. Night Haunter was tortured all his life by terrible, dark visions of the future, and this generated a level of psychic anguish and despair that set him apart from his fellow Primarchs. His psyche damaged by the difficulties of his early life, Curze never recovered his mental balance and sought only oblivion from the pain of his reality.
He was a brutal warrior who believed in the use of fear as the most potent weapon against one's foes, and he taught his Astartes to be as brutal and savage as necessary to put down the enemy. Night Haunter did not enjoy his role as an Imperial war leader and was the only one of the Primarchs who showed little affection for his "sons," the Space Marines of the VIIIth Legion that had been created from his genetic template. He was slain, some believe willingly, by the Callidus Assassin M'Shen on the world of Tsagualsa in the Eastern Fringe of the galaxy immediately following the end of the Horus Heresy in the early 31st Millennium. His VIIIth Legion, without his leadership, then broke up into competing warbands and fled into the Eye of Terror with the rest of the Traitor Legions.
"We have come for you!" or "Ave Dominus Nox!"
The Night Lords were originally the VIIIth Legion of Space Marines created during the First Founding and became one of the 9 Traitor Legions of Chaos Space Marines that betrayed the Emperor of Mankind during the Horus Heresy of the 31st Millennium. They do not worship any of the four Chaos Gods individually, but acknowledge them equally in the form of Chaos Undivided as they ruthlessly spread terror and fear amongst the galaxy's inhabitants. The Night Lords are experts in the use of terror tactics to win battles and demoralise their foes before the main combat even begins. The Night Lords are synonymous with terror and murder, for their favoured mode of warfare is the unfettered application of brutal, overwhelming force. They show no mercy whatsoever, eschewing all subtlety and guile for wanton bloodshed and destruction. While such an approach might appear mindless, at one time it was different.
Ten millennia ago, the Night Lords' Primarch Konrad Curze was driven to acts of extreme violence by a deep-rooted desire to punish the guilty and impose order upon the anarchy in which he grew up. Only later, when the doomed Primarch surrendered his soul to the Ruinous Powers was his relentless drive for justice perverted into the form it now takes. While many of the Primarchs were raised by those peoples they found themselves amongst after the Ruinous Powers scattered them to the corners of the galaxy, Konrad Curze grew to maturity in very different circumstances. The world of Nostramo was a lightless industrial waste, its cities teeming and anarchic and its main export the raw adamantium found beneath the surface. Curze survived as a wild thing, living in the lowest depths of the hive cities and competing for food with the vermin and scum of the sewers. Like all of the Primarchs, he matured quickly, bearing witness as he did so to the most horrific excesses of Nostromo's corrupt society. Murder was rife and the people lived in constant fear. No natural light lit the alleys and the depths, and all manner of fell criminals lurked within them. Soon, Curze began to prey upon these criminals, mounting their mutilated corpses where all could see and take heed. The terror that stalked the streets exacting vengeance upon the lawless soon became known as the Night Haunter, and so fearful were the people of his judgement that soon all, not just the criminals, locked themselves inside their dwellings, and a peace of sorts was imposed.
As with most of the Primarchs, by the time the Emperor found Konrad Curze he had risen to a position of dominance over his world. Curze's rule was not one of beneficence, however, but one of fear and repression. The people of Nostromo had been entirely delivered from the predations of criminals, but not by way of enlightenment or order. Rather, the people knew that even the slightest malfeasance would result in Curze himself visiting death upon the criminal. When the Emperor presented Himself to the Primarch, the people believed that a new age had arrived. Yet, when the Emperor took Curze back to Terra, Nostromo was plunged back into anarchy, for no one was left to enforce order. Despite the brutality of his methods, Konrad Curze's actions appear to have been motivated by a deep, if twisted, sense of justice. In the brutal underworld in which he had matured, the Primarch had learned that only total dominance would suffice and that to show any sign of weakness was to invite treachery. Even when Curze joined his brothers in the glorious campaigns of the Great Crusade, he appeared to hold to such views, eschewing such notions of hope and optimism which drove others to instead believe in the dark realities of the natural order. He remained sullen and introspective, and shunned the companionship of his brothers. He preferred the company of the warriors of his own Legion, the Night Lords whom he indoctrinated into his favoured methods. Even before the outset of the Horus Heresy, the Night Lords were using methods most others would have denounced as brutally unnecessary and cruel. The Night Lords conquered utterly those who did not welcome the coming of the Great Crusade, crushing all opposition in such an overwhelming and brutal fashion that no others would dare resist.
As with so many of the Primarchs who rebelled against the Emperor and all they had been created to stand for, Konrad Curze crossed a line from which there was no return. Having clashed with Rogal Dorn, he was censured by his brothers, who convened a council to consider the matter of their darkling brother. Curze however slew his guards and fled, outrunning his pursuers and returning to Nostromo. There, he enacted his final revenge upon a society that had descended back into the corruption from which he had strived so hard to deliver it. The Night Lords fleet targetted a weak point in the planet's crust and unleashed every weapon in their arsenal, destroying Nostromo and, some would say, damning Konrad Curze for all eternity. When the Warmaster Horus revealed his treachery and plunged the galaxy into the fires of civil war, Konrad Curze threw himself into a bitter campaign of death and destruction, giving full vent to his most violent urges.
It was never sufficient to simply defeat an enemy army. Curze taught his Legion to make an example of those who stood against them, to destroy their enemies' cities, slay their kin and display their broken corpses as a message to all others. His Legion wreaked bloody murder across the galaxy, which continued even after Horus' defeat at the height of the Siege of Terra. Curze did not fall during the Horus Heresy, and neither did he receive the dark blessing of the Ruinous Powers in the form of apotheosis to daemonhood. Instead, he met his end at the hand of an assassin of the Callidus Temple. It is known that throughout his life Curze was struck with powerful visions of the worst of all possible futures, and that his last had been a foretelling that he would die at the hand of one such as she. Alone of all the Primarchs, Curze welcomed his death, apparently allowing the assassin to take his life. It is said that in so doing he attained that which he had always craved -- vindication. The Primarch's acceptance of his own fate confirmed his bleak worldview, granting him a victory he could never attain under the rule of his father. It is a view still held by the gene-sons who survived him to wreak an eternal campaign of blood and shadowed terror against the Imperium of the Corpse Emperor.
The ranks of the Vth Legion were swelled by the intake of warriors inducted from Jaghatai Khan's fierce army, the Legion inheriting the traditions of the Chogorian steppes nomads. Soon, the savagery of the tribes had bred itself into the Legion's gene-seed too, but it was tempered by the fierce sense of honour and justice embodied so perfectly by the Legion's Primarch. The White Scars fought with valour and determination throughout the Great Crusade, though the years immediately preceding the Horus Heresy were spent mired in a campaign against an Ork Empire centred on the Chondax System.