Dark Angels - Legion Operational Doctrine: By the last years of the Great Crusade, shortly before the outbreak of the Horus Heresy, the Dark Angels claimed a strength of approximately 180,000 warriors. In terms of sheer size this placed them in the upper tier of the Legiones Astartes, alongside such Legions as the Ultramarines and Sons of Horus, and despite the rise of the younger Legions to rival their glory, they still remained one of the single most powerful military forces in the Imperium. Some surviving records from the period have noted a much lower field strength for the Dark Angels, sometimes as low as 50,000. These reports are likely due to the confusion that the Dark Angels' organisational procedures and heraldry caused for most unfamiliar observers.The dense nature of the ciphers they used and the secretive nature of many of its sub-formations often led to some amount of bewilderment for outsiders, especially when combined with the fluid and shifting nature of authority and command within the Legion, sometimes even to the degree that it led to military setbacks when working alongside other Imperial forces. Surprisingly, the Dark Angels made little attempt to remedy this situation, indeed some of their commanders, especially the older veterans of the Great Crusade, seemed to take a quiet pride in the confusion it occasioned among the least disciplined of their allies.In particular, a common practise by some Dark Angels Legion forces was to arrive without announcing to their allies who commanded the Ist Legion's contingent, leaving their counterparts to determine whom to greet as warlord by the heraldry they displayed. Those few who made the correct choice, or who were wary enough to make no judgement, were treated with respect and those who chose poorly watched carefully for further lapses in judgement. Such tests of worth were commonplace among the Dark Angels, both for their own initiates and for those that would fight alongside them, for the sons of the Lion judged the worth of no warrior on rumour and hearsay alone.Such actions were most often encountered among the more veteran formations of the Legion. Those forces whose tallies of victories and vanquished foes were so impressive that some among the newly-recruited regiments of the Imperium's armies thought them fabrications and even those who had served in the Great Crusade long enough to have heard of the valour of the Ist Legion rarely knew the full scope of their victories and sacrifices.Indeed, the Dark Angels remained one of the most experienced bodies of warriors within the Legiones Astartes. Despite the many dire battles they had faced, they had always retained a core of Veterans to pass on the hard-won skills and knowledge of their struggles, indeed much of the structure of the wings of the Hexagrammaton and the orders of the Hekatonystika was dedicated to exactly this task. As such they had maintained a level of skill and proficiency in every sphere of warfare that, while sometimes less specialised than the younger Legion, could rarely be equalled among the Legiones Astartes.Given these material and organisational preferences the Dark Angels tended to a sparse pattern of deployment, scattering their numbers widely in relatively small detachments, relying more on the potency of their weaponry and the individual prowess of their warriors than on sheer numbers. Capitalising on the diverse nature of the warriors that made up each chapter and company, individual battle forces of the Dark Angels were most often little more than a handful of chapters operating in close support, often a force as small as a few thousand warriors. Where other fleets relied more on the numbers they could bring to bear, the Dark Angels emphasised the fluid nature of their units which were able to quickly and efficiently reform as needed within a local theatre of war in order to meet the challenges of a given engagement.It was a rare sight to see large numbers of the Ist Legion gathered in any one place, and such a sight was considered a portent of the worst kind, for the grim, black-armoured ranks of the Dark Angels were only amassed to face the most dire of threats. Indeed, many among the ranks of the Imperial Army considered it a grave misfortune to be tasked with serving as support to the Dark Angels, not due to any mistreatment at the hands of the Legiones Astartes, but rather because the battlefields upon which they walked were inimical to the lives of merely mortal warriors and only the most skilled or fortunate mortal soldiers survived such a tour of duty. Despite this long-held superstition, those few regiments that had served alongside the Dark Angels and survived held the battle honours granted them by the Lion with pride, despite the bloody price paid for their acquisition.In order to support this widely spread web of independent companies and chapters the Dark Angels maintained perhaps the greatest fleet of all the Legiones Astartes, both in terms of sheer number of capital class vessels and in the impressive firepower of those craft. Just as with the many disparate companies of the Legion, the fleet was also widely spread, most often operating either as a support flotilla attached to a chapter or as one of the rare deep range patrol squadrons.Support flotilla were comprised of the heaviest void ships available, with the core of many being a Gloriana-class Battleship or other first-rate warship supported by one or more squadrons of cruisers. Support flotilla were intended to provide transport for the attached chapters, allowing them to breach heavily-defended star systems without support and assault a specified target without the need for extensive auxiliary forces. They also served to provide orbital fire support to Legiones Astares forces engaged in battle and a base for Legion interface craft, either to serve as an orbital supply line or to launch airstrikes or interdiction missions.By contrast, the patrol fleets maintained a smaller contingent of Legion warriors, rarely more than company strength, and fielded more deep range cruisers and sleek escort craft mounting scanning augurs and other equipment unique to the Dark Angels. These squadrons were tasked with seeking out unknown nests of xenos or isolationist and belligerent Human enclaves, much in the same manner as the more specialised White Scars fleets.Those Legiones Astares companies accompanying the fleet were used solely to assess the threat level of the enemies discovered, mounting spoiling raids or brief hit-and-run campaigns before withdrawing back to the orbital fortresses. Those deemed dangerous by the veterans of the Ist Legion were annihilated from orbit and those marked vulnerable left for the Great Crusade that followed in the fleet's wake.With assets spread across the galaxy, the Ist Legion placed little emphasis on maintaining a large number of holdings and fortresses. Indeed, there were only two large outposts held by the Dark Angels, the ancient fortress of Gramarye which played host to the halls of the Council of Masters and the vast industrial facilities that produced many of the Legion's more esoteric weapons and had long been concealed from the scrutiny of the Mechanicum, and the more recently acquired fortress-monastery of The Order on Caliban. These two worlds saw the largest concentration of the Legion's infrastructure, and were both heavily fortified and defended.Other holdings on Terra, where a significant protion of the Ist Legion's recruitment was still conducted, and the scattered chantry houses of the various Orders Militant, were less well defended, but not intended as frontline combat installations.The standard pattern of operations within the Legion saw these holdings used as bases for resupply for a force that was primarily based within the mobile halls of the fleet. Only on the rarest of occasions did any of the chapters of the Dark Angels Legion return to their halls for any lengthy period of rest, with garrison duty left to the rawest recruits and those masters and seneschals with Deathwing lifeguard cadres that stood warden over those domains.