Space Wolves - Pre-Heresy: When Leman Russ took over the VI Legion, it adhered rigidly to the guidelines and dispositions laid down by the Principia Belicosa of the Imperium's High Command. This rule was clung to by the warriors of the Legion as an anchor against the disorder their own increasingly fractious character was sowing in their ranks. Enforced discipline was common and even executions in the field were not unknown in the VI Legion.With the rediscovery of Leman Russ and the cultural influence of Fenris which he imprinted on the Legion, these factors rapidly fell by the wayside. The fury which lay within the Legion's heart was given form and discipline mastered by will, and this wellspring of savagery was channelled and directed in battle rather than left unfocused, providing a catharsis which purged the Legion of its self-destructive tendencies and unified it under the Wolf King's banner.Both the Fenrisian way of warfare as adapted by Leman Russ and the natural tendencies of the Legion to want to close and get to grips with its foes at close quarters led to a rapid and shifting focus away from the generalist and combined arms approach advocated by the Principia Belicosa and towards tactics dependent on highly mobile shock infantry units, with heavier support elements maintained, but largely focussed in specialised detachments rather than as part of the general line of battle.The Space Wolves were conditioned to hold a near-suicidal disregard for danger and trained to exploit this to the fullest on the battlefield, pitting their courage and might where it would be most effective; in the very teeth of the foe, overwhelming opponents by sheer speed and ferocity of attack, both in hand-to-hand combat and in brutal short-ranged fire fights.As time went on, their tactical dispositions shifted to better accommodate this preference, leading  to the creation of unique shock units such as the "Grey Slayers" and "Bloodied Claws," which gradually came to comprise the bulk of the core infantry of the Legion by the time of the Burning of Prospero.By the late Great Crusade era, the Space Wolves Legion had strongly deviated from the Principia Belicosa's definition of the Legiones Astartes structure and organisation, although they could, if pressed, readily enunciate how each warrior would fit in such a structure should it be needed. At the macro level, the Legion consisted of thirteen "Great Companies" designated by their number in the order of battle, with each nominally composed of a theoretical 10,000 Astartes, though in practice attrition and casualty rates meant this was never more than a notional figure.Below this strategic level, the Legion's host was now broken down into a shifting array of ad hoc formations either put together for a particular mission or beholden strongly to the personal authority of a particular company commander, and below them to a series of tributary sub-commanders, known variously as "Wolf Lord" (Jarl) or "Claw Leader" (Thegn), regardless of their notional  or accorded rank within the Imperium's standard order of battle. These warband-like forces -- while each was part of one of the overarching Great Companies which comprised the Legion -- were largely autonomous and heavily infantry-focussed.They often lacked certain specialised units and formations found in other Legions, and could range in size from between battalion to Chapter strength in conventional terms, while below this, the more general terms of "Pack" or "Claw" became an accepted descriptor of any small tactical unit, be it a single squad of warriors or a small combined taskforce. These arrangements could be confusing to outsiders with, for example, a particular Great Company having within it several "Jarls," whose relative seniority or areas of command were far from clear to any but the Space Wolves.These warband-like forces -- while each was part of one of the overarching Great Companies which comprised the Legion -- were largely autonomous, heavily infantry-focussed and often lacked certain specialised units and formations found in other Space Marine Legions. Particularly, this bias left the later Space Wolves Legion lacking in units dedicated to areas of warfare such as siegecraft or sustained bombardment, which did not sit well with the Legion's military philosophy or the psyche of its warriors. Elsewhere in the Space Wolves' wider ranks, the remnants of such specialised forces remained as reserve elements under the direction of the Primarch's household and the direct command of the "Iron Priests" -- the masters of the Legion's armoury -- but such formations became the exception rather than the rule in the Space Wolves' order of battle.Of particular note within the Legion was the role played by the so-called "Priests of Fenris." This sealed chamber within the Legion embodied much of the special command functions provided by the separate Apothecarion, Librarius and Armourium in other Legions. They were suffused both with an aura of ritual and secrecy, unusual for a pre-heresy Legion, for as well as the continuation of the Legion's martial culture, the maintenance of its wargear and the preservation of its gene-seed, these "priests" also occupied the role of keepers of the Legion's occluded history and superstitions, and served as the wardens of its secrets. The senior representatives of this varied priesthood, be they Priest of Iron, Caster of Runes or Speaker of the Dead, had a place of honour on the Einherjar, the Legion's council of war, which advised their Primarch, and on which every Jarl and Thegn had a place, and where every warrior of the Space Wolves had the right to speak.The Space Wolves Legion was a close-knit brotherhood and there was a great deal of respect and comradeship between the original VI Legion Astartes from Terra and the warriors of Fenris. Although the latter troops were organised into their own distinct squads, known as Fenris Bloods and Fenris Hunters, they also led some of the squads of Terran Space Wolves (the Hunter, Claw and Long Fang squads). The officer corps and the elite Wolf Guard were drawn from the ranks of both Terrans and Fenrisians. Both Terran and Fenrisian Space Wolves could succumb to the curse of the Wulfen. This condition was usually diagnosed during the process of surgically and psychologically modifying a normal man to become a Space Marine, but it could also strike later in a Space Wolf's life. The curse was akin to the mythical state of lycanthropy from the legends of Old Earth -- the smitten warrior would become savage and beastlike in behaviour, unable to quell the rage inside. The Wulfen were remarkably hirsute, even by Space Wolves standards, and their canine teeth grew into large dagger-like fangs. All of the Wulfen were assigned to the 13th Great Company and fought together in feral groups known as Wulfen Packs.