13th Black Crusade - Adeptus Astartes Reinforcements: A number of other Space Marine Chapters contributed to the overall defence of the Cadian Gate during the 13th Black Crusade. These Chapters included:Harbingers - Although they had most recently been purging Orks from the Piscinan Belt, the Harbingers Chapter had an old score to settle with the Death Guard. The Chapters' enmity towards these Traitors could be traced back to a raid on their homeworld of Birmingham, "the Black Planet," by the Death Guard, aided by the infamous Renegade known as Fabius Bile. Their Chapter Master, Nimrod Grudge, received early word of the outbreak of the Plague of Unbelief and mobilised the Chapter accordingly. Leaving most of the Chapter either in the Piscina System or on the Black Planet, the Harbingers' 1st, 4th, 7th and 9th Companies boarded their Battle Barge, Unrelenting Fury, and set course for the world of Nemesis Tessera. Immediately upon their arrival they were recruited for a special mission. As the Harbingers were known for their skill in the art of boarding Space Hulks and launching planetary assaults, it could only be assumed that their mission involved the use of that particular skill set.Marines Exemplar - Led by their Chapter Master, Commander Maxim Absolon, the Marines Exemplar committed all but a single Reserve Company to the defence of the Cadian Gate early in the conflict, arriving less than a solar week after the Space Wolves Chapter. Accepting Logan Grimnar as the more experienced commander, Absolon allowed his companies to be deployed according to the Great Wolf's strategy, which saw them despatched across all the warzones of the segmentum to bolster those Imperial defences most in danger of falling. Tragically, Absolon was lost in the opening phase of the conflict, as his company attempted to extract the senior staff of an Astropathic way station before the forces of Abaddon overwhelmed the jungle moon on which it was located. The 5th Columnus Regiment, a Traitor Guard unit led by the demagogue Colonel Jobe, was making a push towards the Belis Corona System, but had first to secure the jungle moon. Greatly outnumbered, Absolon led his force in a desperate breakout, and although the majority of his company escaped, the commander's Thunderhawk gunship was shot down, exploding as it failed to clear the jungle canopy. Absolon was listed as missing in action, though the Marines Exemplar did not give up hope that he might have survived the crash and was still active behind enemy lines. However, Absolon's second-in-command and successor, Captain Raoul, distanced the Chapter from Logan Grimnar's Adeptus Astartes command council, preferring instead to deploy the companies of his Chapter as his own advisors saw fit.Sons of Dorn - The Sons of Dorn Chapter deployed the bulk of their Chapter in the defence of the Imperium from the predations of Abbadon the Despoiler's 13th Black Crusade. They valiantly defended the same worlds along the Eye of Terror that their Chapter's legendary hero, Alexandros the Great, had liberated millennia earlier. More than half the Chapter was involved.Subjugators - The Subjugators Chapter despatched three companies directly to Cadia within solar days of receiving word that the Despoiler had returned, vowing that the remainder of the Chapter's resources would be mustered as soon as was possible. The Chapter arrived aboard two mighty Battle-Barges just as the Chaos warfleet was commencing its initial invasion of the Cadia System. The Subjugators threw themselves straight into the conflict, during which the 3rd Company distinguished itself by triggering the reactor overload that destroyed one of the Ramilies-class Starforts orbiting Cadia, at the very moment the Forces of Chaos gained control over it. Only a handful of the 3rd Company escaped the subsequent explosion, but their heroic sacrifice undoubtedly saved the lives of many thousands of Imperial defenders on the surface of Cadia, who would otherwise have found themselves facing the might of the starfort's guns. Yet the Subjugators were reduced to a state of disarray after losing the majority of the 3rd Company in this manner. The 1st and 5th Companies took heavy casualties during the Siege of Cadia itself, notably in the defence of Kasr Gallan and the subsequent rearguard actions during the desperate Tarn Retreat, and were in serious need of resupply. The Subjugators were a recently Founded Chapter, and as such, maintained only small reserves of gene-seed. The loss of the 168 Battle-Brothers who fell on Cadia was a terrible blow to the Chapter, particularly as the Subjugators' Apothecaries were in most cases unable to recover the gene-seed of the fallen. The Chapter was eventually faced with the choice of whether to retire from the conflict and regroup, allowing time to rebuild their numbers, or to fight on regardless, and risk the death of the Chapter through sheer attrition, before it had even had a real chance to make its mark in the annals of the Imperium.White Scars - The first contingent of White Scars to reach the Cadian Gate was the Brotherhood of Khajog Khan, a leader known for his victories during the Third War for Armageddon and a dozen other campaigns. Khajog led his force against the Chaos hordes massing on Cadia, launching a series of devastating hit-and-run attacks across that world's bleak moors. Within a short period of time Khajog's Brotherhood had become a major threat to Abaddon's plans, striking deep within enemy-held territory. So effective were their actions that the sieges of Kasrs Myrak, Soliq and Rantik were lifted as Chaos forces were diverted to hunt down and confront the elusive White Scars. It would seem that Khajog's attacks were in fact too effective, for Abaddon himself ordered the Brotherhood hunted down and destroyed once and for all. He knew that the White Scars planned on diverting his forces piecemeal to oppose them, but he reasoned that a full-scale response would be beyond the scope of the small Loyalist force to face. Ordering the 1st Company of the Black Legion, as well as uncounted hordes of mutants, Traitors and Chaos Cultists out onto the moors, the Despoiler began his hunt. It was through the divinations of Abaddon's most senior advisor, the Chaos Sorcerer Zaraphiston, that Khajog was finally located. Unaware that his force was being watched through Zaraphiston's scrying, Khajog launched a raid against an enemy slave train west of Lake Terror, only to discover that the convoy contained not Imperial prisoners, but the Chosen of Abaddon. The first wave of White Scars bikers hit the convoy, only to find themselves hurtling headlong into the guns of the Black Legion. The four Bike Squads, realising they stood little chance against such a foe, continued their charge nonetheless, determined to buy time for the other warriors of the Brotherhood to regroup. The warriors of the first wave sold their lives dearly, and Khajog reluctantly ordered his men to withdraw, vowing that he would return at a time of his own choosing to avenge the deaths of his Battle-Brothers. But Khajog did not get to choose the manner of his next confrontation with the enemy, for as his Brotherhood sped across the moors they found every route cut off by the Forces of Chaos. At length, Khajog decided that to flee in the face of the enemy was an insult to the honour of his Chapter, and resolved to make a last stand at the base of a Pylon on the shores of the Caducades Sea. With the Pylon to their backs and the massed hordes of Chaos to their fore, the warriors of Khajog's Brotherhood chose to defend themselves according to the ancient traditions of their homeworld of Chogoris by launching a suicidal charge against the enemy. The 60 White Scars smashed into a horde at least fifty times their own number, Khajog Khan at their head bellowing the battlecry of his Chapter. As the Brotherhood smashed through the ranks of the horde, its warriors were torn from their saddles, one by one falling to the sheer weight of numbers arrayed against them. Khajog rode his own Attack Bike through a sea of mutated bodies, clawed arms and whiplash tentacles seeking to drag him under with every metre he gained. Khajog Khan was the last of his Brotherhood to fall that day, and the Stormseers of the White Scars claim that his shade remains upon the shattered ruin of Cadia, unwilling and unable to return to the Chapter's homeworld of Chogoris until vengeance is visited upon the heads of those who slew him.