The was a code developed by the Primarch of the , . This tome would contain everything a member of the Astartes would need to know to function. From recruitment to organization to tactics and beyond, the Codex Astartes became a sacred text to the majority of the Chapters. The Space Wolves Legion never fully accepted the new doctrine. Rather they hold sacred the teachings of their Primarch. One of the most significant changes within the new Codex was the newly founded Chapters. Where the Legions could number more than 10,000 strong the Chapters would be limited to about a thousand. Each original Legion would be divided as many times as needed into Successor Chapters. This division would come to be called the Second Founding. The remaining thousand bodies in the original Legion would survive as a new Chapter of the same name, while their newly created Chapters would claim their founders origins and be known as their Founding Chapter. Beyond this however the chapters would operate independently, and come to develop their own namesake, culture, and customs. One of the few ideals the Codex implemented that the Space Wolves Legion actually accepted was the succession of Chapters. However, the Space Wolves Legion was never very large. This, combined with the genetic instability of the legion and grievous losses to their gene-seed in the of led to the Legion only founding one successor Chapter, the ill-fated .. After the Wolf King informed the Dark Angels' commander of the wider events of the Heresy, and an exchange of men and materiel, the Space Wolves set course for the Throneworld and the inevitable confrontation with the Traitor Legions.. During the Great Crusade and Horus Heresy the Space Wolves were a Legion with Leman Russ as its King and supreme commander. Like today, the Legion consisted of the thirteen Great Company 's. Russ in turn ruled through a council of Wolf Lords , Wolf Guard , Rune Priests , and other advisers known as the Einherjar ..