Dark Angels - The Emperor's Own Angels of Death: This was an honour they would bear throughout the war to unify the Sol System and beyond, a duty that kept them separate from the other Space Marine Legions created in their image. As the younger Legions slowly began to reach the nominal strength required for the beginning of the Emperor's Great Crusade, the Ist Legion conducted a lonely vigil far from the light of Sol, scouring clean the Oort Cloud and keeping watch along the heliopause border of the system for those terrors that sought to slip unnoticed into the Emperor's newly-claimed domain. This duty they accepted without complaint, taking pride in the role selected for them by the Emperor, for they were His "Angels of Death" -- a name which, at that time, belonged to them alone.For nearly a solar decade they would dwell in the lightless depths of Mankind's home star system, burning clean the frozen moons of the outer system and freeing the few lost outposts of Humanity that still survived at the very outermost edges of the Sol System. Here, the informal network of specialists within the Legion became the first of its formations called "Orders," dedicated to a singular focus of war beyond the wider scope of the Legion's existing hosts; their craft honed in the battles at the dark edge of Sol, and the complex ciphers and rituals by which they recorded it entrenched over the long years of isolation. It was by the hard-won knowledge of these warriors that the Legion would prevail again and again in the most gruelling and hazardous battlesfaced by the warriors of the Emperor, the weaknesses of each foe exposed by sacrifice and encoded in the traditions of the Orders and the secrets of war in any environment catalogued in their archives.The Legion would return to the inner worlds purged of weakness and hardened by adversity, their armour no longer the flat grey of the other Legions, but a deep and impassive black. There would be no fanfare on their return to the Emperor's side, no parades of victory, merely the silent approval of the Emperor of Mankind and a place at the vanguard of the host that mustered ready to make war upon a hostile galaxy to save Humanity from extinction. Despite the hardships that would await them and the mighty foes they would face, none could doubt victory having witnessed the grim resolve and stoic pride in the faces of the black-clad warriors as they took their place at the head of the host.There, amid the vast muster that took place around the shipyards of Saturn, the fleet granted to the Ist Legion stood out among the newly-built Saturnine pattern vessels and the ancient ships re-awakened from the macro-vaults of Mars, for the Ist Legion were granted the honour of a tithe of those few remaining Terran starships. These ancient voidcraft almost all dated back to the years before Old Night, relics of forgotten technologies and lost aspirations of grandeur. Among them were to be found massive Gloriana-class Battleships, Promethean-class Cruisers clad in dense layers of Void Shields and weapon-studded Tiamat-class Destroyers, all far surpassing more modern designs in potency and made available to few other than the Emperor's own guards. To each of His other Legions He bequeathed but a handful of such ships, while to the Ist Legion He granted a fleet.This gift was not a simple reward for the heroics they had displayed in the fighting on Old Earth and beyond, but rather a necessary tool for those actions yet to come. For as the armies of the Emperor set forth on the Great Crusade and pushed beyond the edges of those few star charts that had survived Old Night, they encountered such terrors that the battles on Terra were made to seem inconsequential by comparison. In these dark places among the stars, the Ist Legion would find the reason for their reward, for in order to fight the monsters the Emperor had foreseen in His path, they would need monstrous weapons. Alone among the Legiones Astartes, they would make common use of the forbidden weaponry of Old Night, of gene-phage and rad wave, employed to wipe clean the nests of those enemies deemed too terrible to be faced in open battle. The Ist Legion were the fulcrum of the Emperor's wrath, the agency of His hate, for they brought not simple destruction but the all-encompassing oblivion of utter annihilation.They were the Angels of Death, a title that would one day encompass all of the Emperor's Space Marines but, in those brutal early days of conquest and blood, it was theirs alone.Even as other Legions fought to bring those Human colonies discovered by the expeditionary fleets to Imperial Compliance, the Ist Legion fought to hold back the hate of a galaxy filled with terrors. They took war to the dens of monsters and legends without fear or hesitation, shattering the hold of nightmares on the future of Mankind; though only in the most secure vaults of the Imperial Archives do any records of these battles remain.They speak of Behtelgen IV, where the 3rd Chapter, formed mainly of warriors from the Hosts of Stone and Iron, assaulted a world whose mountains and crust had been hollowed out to form a fortress for a swarm-creature of protoplasmic and hyper-acidic slime, the nucleus of an infection that had spread through the void to infest a dozen worlds and seen millions rendered into little more than a nutrient slurry for the beasts.Scattered picts show the shattered husks of the once-verdant worlds of the Osiryne Cluster where the Ist Legion's 19th Expeditionary Fleet engaged a vast, sentient planet-killer -- a technological abomination spawned by some long-forgotten empire and left to wreak havoc upon an uncaring universe -- the records of the battle itself sealed by Grandmaster Hector Thrane. These horrors, and a thousand more, were exterminated by the warriors of the Ist Legion, and all trace of the campaigns erased from records to protect the sanity of those unprepared for the raw mindless hate of the universe laid bare.To those outside the ranks of the First, their record in the early years of the Great Crusade seems at best lacking in comparison to their brother Legions and at worst a fabrication. With many of their greatest triumphs shrouded in secrecy, they had less conventional triumphs to their name: merely a handful of worlds brought to Compliance where hundreds had burned in silence. What few knew was that it was in the sacrifice and valour of the Ist Legion that many of the Legiones Astartes' key doctrines were forged, with such tomes as the Principia Bellicosa formed, in part, from the strategies and tactics perfected by them as each of the Legion's hosts strove to refine their own brand of warfare upon the most vile battlefields of the Great Crusade.Those that thrived on the field of battle would grow and pass their knowledge on, not only to their battle-brothers within the Legion but to those without through the doctrines created in their wake. While those that struggled would fade from the rosterof the Legion, ground to extinction by the inexorable hunger of war.