Rangdan Xenocides - Second Rangdan Xenocide: In 862.M30 the Rangda returned to Imperial space, marking the start of the Second Rangdan Xenocide. They came not with a single, small fleet, but with a vast armada comprising thousands of vessels as well as over a dozen war-moons, a force of might far exceeding that of the small garrisons and expeditionary fleets in the area. They struck the northern fringe of the Imperium like a thunderbolt, annihilating the fleets set in defence over the fledgling Human colonies and forcing their colonists into neural shackles. It was only by the efforts of expeditionary fleets under the banner of the Vth and XIXth Legions that the xenos tide was delayed long enough for Imperial forces to rally, and the price they would pay to buy this respite was staggering.Making a stand at the isolated Forge World of Xana II, the combined forces of the Vth and XIXth Legions fought a bitter holding action for eight solar months at a cost of 3,000 of the Legiones Astartes and many hundreds of thousands of Mechanicum thralls. The siege of Xana would be broken by the furious onslaught of the Dark Angels and Death Guard, shattering the Rangdan blockade and cutting a path through the Rangdan slave cohorts on the surface to once again open up the Forge World as a beachhead for the Imperium's counter-attacks on the Rangda's domains.What would follow was more than two solar decades of war out among the Halo Stars, millions upon millions of deaths, 19 inhabited star systems laid waste and a ban on further Imperial expeditions past the exclusion posts on the worlds of Endyris and Morox. Before the crisis was declared ended, contingents from nine separate Space Marine Legions would become embroiled in the fighting, with more than 300,000 Space Marines being deployed at the height of the conflict during the climactic Imperial assault by the Primarch Lion El'Jonson on Taxal.Due to the widespread nature of the campaign, the battle honour goes to no single warlord, though three of the primarchs were known to have led their warriors into battle against the Rangda. Despite this, the primarch of the Dark Angels is widely held to be the foremost commander of the war.The last known battle of the Second Rangdan Xenocide is thought to have occurred in 882.M30, a chance Imperial encounter with a battered Rangdan fleet, a broken remnant of the vast armada that had challenged the Imperium and lost. At the time the truth of the Rangdan campaign, of the slaughter endured and how the Imperium had teetered on the brink of ruin, was concealed. Those worlds tainted beyond recovery by the Rangda were abandoned and the surviving veterans of the war sworn to silence or eliminated, for it was deemed necessary that the Rangda must vanish if the Imperium was to rebuild. Much of its legend would come later, the invention of Remembrancers and ideologues eager to promote the glory of the Great Crusade, and was composed of as much fiction as fact. For most citizens of the Imperium this marked the end of the wars with the Rangda, an end to one threat among thousands. A simple, if bloody, way marker in the Great Crusade's inexorable path to galactic conquest.Much of what happened during this abyssal conflict is still locked under seal, but what can be said is that with the breaking of the "Labyrinth of Night" by the Emperor Himself, the threat was at last stymied. What remained was for the Rangdan taint to be purged in a subsequent solar decade-long series of bio-pogroms that left entire Human-inhabited sectors lifeless to ensure what was hoped to be a final victory.After this conflict, the Dark Angels Legion created the Order of Broken Claws to study the Rangda and prepare for the possible return of the horrific xenos species. With access to the detailed catalogue of anatomical data compiled by Firewing operators and Dreadwing cheirophages, the adepts of this order of the Dark Angels' Hekatonystika were trained to stand against the worst Rangdan bio-forms in combat and emerge victorious.