Anyway, for now, enjoy a preview of the fluff section, in the form of one of those timelines GW's been doing in all their books for a while now.
The Lords of Oblivion have defended the Imperium for over a thousand years. During this time, they have seen both heroic victory and sorrowful loss. Recorded below are some of their most notable events.
880.M40-881.M40 The Sco’Ken Cluster Campaign
The Chapter’s first campaign sees them victorious over WAAAGH!!! Gitsmacka, which had threatened a series of mining worlds responsible for providing promethium to the entire sector.
901.M40 The Edge of Space
After nearly twenty of years of almost continual campaigning, the Lords of Oblivion have destroyed the Ork empire which gave rise to WAAAGH!!! Gitsmacka. The Chapter continues to push deeper into Ork space, moving upwards relative to the galactic plane, not stopping until they reach the very edge of the galaxy. By then, dozens of worlds have been cleansed of Ork presence, and Rogue Trader fleets traveling in the wake of the Lords of Oblivion begin to colonize some of the now-deserted worlds.
Eventually, thirty-two worlds are colonized in the name of the Emperor, and the name of the Lords of Oblivion becomes known across the entire sector around Firien.
916.M40 An Alliance is Forged
Leading a force of the 2nd and 4th Companies, High Paladin Allerka brings the Lords of Oblivion to Algieba system, which has come under attack by Chaos Renegades of the Oracles of Change. Also responding to the calls for aid are elements of the Storm Fists Chapter. The Lords of Oblivion offer to work alongside the Storm Fists, who are at first reluctant, both because of the youth of the Lords of Oblivion and their heavy number of psykers, but eventually agree.
The battle lasts several weeks, and nearly a hundred Renegades are slain before they withdraw. The psychic powers of the Lords of Oblivion prove invaluable against the warp-based onslaught of the Oracles. The Lords of Oblivion and the Storm Fists depart the Algieba system as friends.
001.M41 A New Era
The Lords of Oblivion celebrate the dawn of the 41st Millenium with a great feast upon Firien, amidst renewed oaths of loyalty to the Emperor and great contests of skill and strength. After a week of celebration, the Chapter launches into a new campaign, engaging in a daring raid against the newly birthed daemon world of Egollarth. The attacks are successful in sealing the numerous warp rifts across the planet, returning it to Imperial control. The Chapter gains a taste for fighting the daemonic.
086.M41 War in the Shadows
Captain Baros leads the 2nd Company in the defense of Mentax against Dark Eldar raiders. Though the xenos strike from nowhere, the foresight of Librarian Velnis, blessed with the Gift of the Seer, allows the Lords of Oblivion to anticipate and destroy the Dark Eldar raiding forces.
161.M41 The Lost Company
The 5th Company, while en route to the Arneb system, is separated in their strike cruiser from the rest of the Lords of Oblivion fleet by a sudden flare of warp activity. Attempts to locate them are unsuccessful, and the Company is declared lost. Over a decade later, the Company and their strike cruiser appear in orbit above Firien, battered but unbroken, and with tales of harrowing fights against Orks, daemons, and other horrors unknown to the Imperium in their quest to return to Firien.
244.M41 The Reclamation of Rholeo IV
Traveling further from Firien than any other member of the Chapter, a strike force led by Captain Felrin of the 3rd Company makes contact with the lost world of Rholeo. Isolated for nearly eight thousand years, the humans had been devastated by alien invaders, and the survivors had formed into petty nation-states in perpetual war with each other over limited resources.
After refusing to return to the Imperial fold, the humans of Rholeo find themselves quickly decimated by the Lords of Oblivion, and a regiment of Firien’s Imperial Guard takes up permanent garrison by right of conquest. With the planet under control, an expedition is launched into some of the older ruins on the planet in response to stories of ancient treasures. Miles beneath the surface is a vast catacomb network filled with countless artifacts. Among them are several Standard Template Construct modules, pertaining to manufacturing techniques.
Captain Felrin brings the modules to Firien, and High Paladin Allerka bequeaths them to the Adeptus Mechanicus upon the forge world of Valtorek as a sign of friendship. In return, the Tech-Priests gift the Lords of Oblivion with fifteen suits of Tactical Dreadnought Armor.
293.M41 The Bringer of Sorrow
A detachment from the 1st Company aids the Brazen Claws in cleansing the space hulk Bringer of Sorrow of Genestealers and other alien menaces.
302.M41 The Moons of Melathras
The 3rd Company comes to the industrial world of Melathras, which is in the throes of rebellion as the worker castes on its dozens of moons rise up in revolt. The revolts are later revealed to be inspired by a Chaos cult that has infiltrated the worker castes, and the 3rd Company conducts relentless cleansing campaigns.
The First Squad in particular gains great honor, as they stand alone against a sudden onslaught of cultists at the main space port of the moon of Telan, fighting against thousands of crazed heretics for three days straight until reinforcements can arrive. It takes hours for the broken bodies of the cultists to be cleared out of the space port following the battle.