Battle of Advex-Mors

The Battle of Advex-Mors was a battle of the First Rangdan Xenocide.^[1]

Overview

The six worlds of Advex-Mors was where the Rangdan were first identified, with the Xenos promptly overrrunning the system and establishing a outpost and creating a vast legions of slave soldiers from the captive Humans. After the Rangda had first been identified as the threat they were by the V Legion, a massive Imperial force mustered at Xana including some 50,000 First Legion Space Marines and 100,000 troops from the Imperial Army and Mechanicum Taghmata, as well as 100 capital ships under the command of Grandmaster Urian Vendraig. Meanwhile, the Rangda had heavily fortified Advex-Mors and construct a vast artificial moon-like battle station with their slave hordes.^[1]

Vendraig hoped to use the battle as a return to glory of his Legion, which in recent years had been faltering. He had the fleet translate out of the Warp in a single wedge formation led by three First Legion Gloriana Class Battleships Invincible Reason, Paradigm of Hate, and Truth's Razor. Using this might, the Imperials quickly swept the few squadrons of Rangda war-barques before them. The invasion of Advex-Mors Extremis followed these initial successes in orbit, with the Grandmaster himself deploying at the head of the 1,000 warriors of the First Legion's 8th Chapter. Extremis only had limited strategic worth in the form of a small fuel refinery, and was garrisoned by only tens of thousands of Rangda slave soldiers. Vendraig eventually was able to identify the Rangdan overlord and slay it himself. Within the span of a few months the Imperial fleet had conquered the four outermost planets and reached the gates of Advex-Mors Primus and the vast artificial moon that hung above it. Knowing that any direct assault on the moon would create massive casualties and leave the planet below time to fortify, Vendraig planned to strike at both at once using his Space Marines. A single Chapter would attack the moon under the cover of a fleet diversionary attack while the majority of the Legion would make a vast planetary landing.^[1]

As the Imperial fleet advanced the Rangda vessels did not rush headlong to meet them but rather formed a defensive formation around the war-moon. Forced into the concentrated guns of the foe, a vicious and bloody naval battle erupted. This was the war of attrition the Imperials had wanted to avoid, but one they could not easily abandon without ceding control of Primus. It took the sacrifice of the Battleship Paradigm of Hate to turn the tide. The ship had been infested by Rangdan stalker drones and badly damaged, slamming into the war-moon and creating a massive hole in its hide before overloading their plasma reactors. Rangdan warriors boarded the vessel and a vicious battle erupted until the vessel exploded, creating a miniature sun inside the war-moon. The Battleship's sacrifice made the naval battle devolve into a chaotic melee that allowed the Invincible Reason and Truth's Razor to blast a path into low orbit and launch a Drop Pod and gunship landing assault. During the first day the initial raiding parties of the Order of Crows and the Hosts of Wind and Fire bore the brunt of the fighting against both the Rangda themselves as well as legions of slave soldiers.^[1]

Vendraig was eventually able to muster 30,000 Legionaries and make his full assault across 100 kilometers of Advex-Mors' broken outlands. The initial stages saw the Space Marines fight slave armies, which they engaged with screening elements of the Host of Blades and the heavy tanks of the Host of Iron. Knowing this common Rangdan tactic Vendraig mustered his finest warriors from the Host of Crowns and the Host of Bones to act as a mobile reserve to counter the expected pinpoint assault that the Rangda themselves would soon make on their lines. Meanwhile, mobile elements of the Host of Wind mounted on Jetbikes and Land Speeders harried the main Rangdan force. Made complacent by earlier conquests, the Rangdan elite watched and waited and expected to face an exhausted foe. However Vendraig moved first, leading a charge that burst through a slave soldier battalion and bore down upon the Rangdan overlords. The Rangda met the First Legion blade-to-blade in a savage melee battle. Vendraig met the Rangdan warmaster in single combat. In the end, though poisoned and badly wounded Vendraig was able to slay the Xenos general, breaking the pride of the Xenos army. The Rangda fled and took shelter in nearby fortresses. However by this point the Imperials had consolidated their holdings in orbit and the next few months saw a series of grueling sieges as the First Legion surrounded and reduced the fortresses to rubble, erasing all trace of the foe.^[1]

Though they were victorious in the end, the cost for the First Legion was dire, having lost 10,000 Space Marines and 50 capital ships. The Paradigm of Hate remained fused with the derelict war-moon, with the First Legion choosing to leave it there as a symbol of what had occurred.^[1]

Sources

• 1: The Horus Heresy Book Nine pg.120-122