”Fear us, for we are the Storm.”
The Wolfbrothers Do Not adhere to the Codex Astartes . Instead their mantra in all matters is the “Song of Saemuel, the teachings of Russ,” also called the ‘Codex Regius,’ within the ancient files of the Imperium. The song consists of the written and verbal traditions of the Wolfbrothers personally selected by the wolf father himself and taught by Saemuel the Wolfpriest. To find it in written form is rare indeed and the Regius copy is one of two versions known to exist, the only copy outside the Wolfbrothers Chapter itself - “recovered” by Blood Legion Space Marines during the first Wars of Eradication.
The wolf-father and Saemuel carefully crafted the Wolfbrothers Chapter. Saemuel was selected particularly for the role of Chapter Master and bestowed the rank of Wolf Lord. Twelve new Wolf Lords were also selected specifically for the new Chapter through numerous and rigorous trials of spirit and ability. Many of the Wulfenkind sensed opportunity and heavy destiny and found rank within the new Wolfbrothers as the Space Wolves Chapter was almost literally split in half.
Bloodclaw, Grey Hunter, Long Fang each then found themselves fighting their way into the new ranks of The Fang, The Fjalar (Sneaky Wolves), The Mjolnir (Elite Wolf Guard) and The Ragna (Revered, Holy Wolves.) The Wolfbrothers would become renowned for the occult surrounding the teachings of Russ, even more then the “firstborn” Space Wolves. Wulfenkind were embraced and many of the original founders bore the mark and rose quickly in rank. This extreme exponent of the Canis gene-seed is not rare amongst the Wolfbrothers by any stretch of the imagination.
Wolf-father occult and Wulfenkind would lead to the near extinction of the Wolfbrothers. The High Lords of Terra would after long debate, decide and declare the Wolfbrothers Chapter corrupt - infested with rampant unstable mutation with no hope of salvation. Several 2nd Founding Space Marine Chapters, notably the Blood Legion of Blood Angel ancestry were sent to exterminate the Wolfbrothers Chapter, and hunt them to oblivion.
The Wolfbrothers were granted stewardship over many of the Space Wolves settlements and installations as well as a few dozen Imperium Worlds to patrol and sanction. The very first Wars of Eradication were the most brutal. Entire populations were destroyed for their “contamination.” All of the Wolfbrothers known cloning facilities and genetic installations were destroyed quickly. Across the stars the Wolfbrothers were slaughtered by the man, pack, and company. Entire Chapters took part in the massacre.
The great wolf father and his prophet had prepared the Wolfbrothers. They saw the treachery of who they called the Aesir (Other Great Sky Warriors – Space Marines.) The entire third section of Saemuel’s song teaches of the Imperium’s brutal “battle with the wolf” - Instructions and dictates on how to prepare for and survive the pending onslaught. Therefore not all of the Wolfbrothers holdings were known and many survive and indeed thrive even to this day. Enormous Wolfbrothers fleets have been found in many engagements with both Xenos and Imperial forces across an awesome swath of Imperial territory. Most recently due to the Tyranid hivefleet invasions of the Imperium, many Wolfbrother establishments have been able to thrive openly.
Being hunted to the brink of extermination has caused an awesome evolution for the Wolfbrothers Chapter. They are resourceful in every way and have learned to exist without the direct support of the Imperium itself. Through the ages the Wolfbrothers have harnessed fantastic autonomous resources. From genetic ‘feeder’ facilities nestled deep within the hard to reach confines of remote asteroid belts to entire mobile-space factories roaming the stars amongst the great nomadic taskforce – The Wolbrothers have definitely flourished since the High lords of Terra made them outlaws.
It is true that many packs of the Wolfbrothers have been annihilated or joined the ranks of the chaos traitors. At times nearly non-existent, the chapter that has survived the Wars of Eradication is fiercely loyal to the Emperor, but acutely wary of the fickle powers and moods of the Imperium. Some of the Wolf Lords have embraced the practice of mercenary or even pirate activity within the Imperium. These misguided souls are called "Dogsoldiers" as both an endearing term of respect or equally loathing insult within the Wolfbrothers Chapter.