Dark Angels - Legion Strength and Disposition: Horus chose the moment to raise his banner carefully, setting plans to have those Space Marine Legions that threatened his revolt divided and distant from the fighting that would decide the fate of the Imperium. The Dark Angels, ever on the move and split across the vast territory of the Imperium, had been subtly divided by the orders of the new Warmaster, set to patrols and campaigns far from Terra and cleared away from the northern bounds of the Emperor's domains.A significant portion of the Legion had gathered under Lion El'Jonson and been dispatched beyond the bounds of the Imperium in the galactic east, beyond news of what was to come and far from those who might call upon them for aid. Both Caliban and Gramarye had seen a sudden drop in shipments of crucial supplies and news from the far front of the Great Crusade, all blamed on the vicissitudes of war rather than the hidden orders of the Warmaster, leaving them gradually more isolated and vulnerable. To any conventional assessment of military strength, the Dark Angels had been forced into a corner before even the first Traitor cannon was fired at Isstvan III.Of their full strength, most likely somewhere slightly less than 200,000 warriors at about 180,000, no more than a third had been dispatched alongside the Lion and placed beyond the reach of the Imperium. This left perhaps 120,000 Dark Angels active along the borders of the Imperium, mostly clustered to the galactic south and west in small battleforces of no more than 5,000 warriors. Most of these forces were either heavily engaged in prosecuting difficult campaigns or fresh from the fields of victory and still counting the toll upon their strength.Few had been given the opportunity to make contact with either the upper echelons of their own Legion's command or that of the Divisio Militaris that coordinated Great Crusade deployments, and the Primarch Lion El'Jonson remained far from the reach of his Legion with no news of his progress or the fate of the troops that accompanied him. The Dark Angels that remained were in essence blinded and by accepted military logic exhausted and as such Horus, his strategists and co-conspirators deemed such small forces to be of negligible threat to their plans, that isolated from any central command they would be unable to mount any real opposition to the rebellion.They were sorely mistaken. Among all the Legions, the Dark Angels' complex system of wings and orders had long defied any foothold to Horus' and Lorgar's treacherous warrior lodges, denying that insidious seed of Chaos corruption that had stymied so many other Legions' ability to react swiftly to the news of Horus' perfidy.Nor were the Dark Angels distracted by the confusion that afflicted the Imperium's control channels in the immediate aftermath of the Isstvan III revolt, for they had long disdained to subject themselves to the direct oversight of the Imperium's authorities. Where other Legions and fleets scrambled to react to the unified onslaught of the Traitor forces and struggled to combat the influence of the Warmaster within their own ranks, the Dark Angels' fleets each took initiative on their own and met this new challenge head-on.Purposefully kept to the outskirts of the initial conflict by the Warmaster's machinations, the Dark Angels' knight-praetors set their chapters upon those outlying worlds that dared to openly espouse loyalty to the Warmaster, deprived of the chance to directly strike against Horus' new centres of power.The Dark Angels turned their disadvantage to opportunity, each fleet an unpredictable threat to the Traitors and their allies, and more than capable of annihilating forces larger than their limited numbers might suggest. The destruction and chaos they wrought kept many star systems and industrial centres along the southern and western galactic rims from supplying the main rebel force as well as threatening the Death Guard homeworld of Barbarus and slowing the rate of troops from that key world to the front.Even as the hastily-assembled Imperial retaliatory task force headed to Isstvan V, the Dark Angels were fully engaged at a dozen worlds far from Terra, utilising the terror weapons at their disposal to make examples of those Imperial worlds most vocal in their support of the Warmaster. The burned and poisoned husks of once-populous worlds were intended to bring a swift end to any insurrection, but could not stem the tide of rebellion that rose up in the wake of the Drop Site Massacre at Isstvan V and the momentum it granted to the rebel armies of the Warmaster.Despite this, the Dark Angels did not hesitate to destroy that which they could not hold in the Emperor's name, preferring to leave Horus as the Warmaster of an empire of ashes than allow their temporary weakness to cede him territory, with only the most heavily-fortified worlds proof against their onslaught.So for the first handful of years of the Horus Heresy the limited size of the Dark Angels' companies restricted them to small-scale raids, with many using the superior void craft of their attached fleets to take on the role of commerce raiders, cutting the throat of the Traitors' supply chain. Gramarye and Caliban, while never directly attacked, were kept isolated from the greater war, both by the actions of Word Bearers esoterists and the strange Warp-based powers they now wielded, and the disturbing silence from certain echelons of the Legion's leadership.The Dark Angels remained a potent force, but one divided and bereft of cohesive direction, at the time seemingly little more than a painful thorn in the side of the juggernaut Horus had aimed at Terra. Yet, with the advantage of hindsight, it is clear that by the actions of the raiding fleets of the Ist Legion, Horus was denied the early victory he craved, for the supplies they denied him and the chaos they sowed amid sectors that might otherwise have fallen to him without a shot fired slowed his advance just enough.The stubborn refusal of the Dark Angels to consolidate and grant Horus' lackeys a final decisive battle, a defiant and suicidal assault to express their anger and frustration, granted the Primarch Rogal Dorn, the Praetorian of Terra, time to rally the remaining Loyalist elements around the Imperium's core. It also kept them from the series of massacres and last stands that plagued the Loyalists during the early years of the Horus Heresy, the carefully arranged decimation by which Horus had removed those obstacles that stood in his way.This carefully chosen strategy left the Dark Angels perfectly placed for the return of their lord, poised at the borders of Horus' fragile empire and ready for the Lion to give the word, to let loose the fetters of Imperial decree and give them leave to unleash all the fell tools they held ready for such a cataclysm. Horus' first gambit had failed, Terra remained outside his grasp and the Ist Legion stood ready to show him the terrible cost of his dark ambitions.