Rangdan Xenocides

The Rangdan Xenocides
Date	ca. 839.M30 - ca. 930s.M30
Scale	Sector-wide
Theatre	The Halo Stars
Status	Imperial victory
Belligerents
Rangdan Cerabvores	Imperium of Man
Commanders and Leaders
Unknown	Emperor of Mankind, Leman Russ, Lion El'Jonson
Strength
Rangdan Cerabvores, Rangdan Osseovores, Slaugth Murder-Minds, Rangdan War-moons	Dark Angels Legion, II Legion, White Scars Legion, Space Wolves Legion, XI Legion, War Hounds Legion, Death Guard Legion, XIX Legion, Ghost Legion, Legio Gryphonicus, Legio Vulturum, Legio Kydianos, dozens of other Legio Titanicus Legions, Knight House Malinax, Knight House Orhlacc, Xanite Mechanicum Taghmata Forces, Centurio Ordinatus, Ordo Reductor
Losses
Unknown, probably total	Massive losses among Imperial expeditionary forces, entire Titan Legions and fleets destroyed, possibly two Legiones Astartes destroyed. At least 80,000 Astartes casualties, including 10,000 Dark Angels at Ardex, 3,000 White Scars and Pale Nomads and 5,000 Space Wolves at the relief of Xana. uncounted millions of Imperial Army casualties.
Outcome
Elimination of the Rangdan threat to the northern Imperium; continuation of the Great Crusade; depletion of the Dark Angels and Space Wolves Legions; Ultramarines become the largest Space Marine Legion

The Rangdan Xenocides were collectively the largest and nastiest fight the Imperium of Mankind faced during the Great Crusade. This was a conflict so horrendous that it swallowed entire expeditionary fleets and Titan legions, nearly crippled the Death Guard, the Dark Angels, and the Space Wolves, and saw dozens of worlds laid waste. Most interestingly, it may or may not also be the reason that the II and XI Legiones Astartes were wiped from all Imperial records.

The Campaign

The Xenocides began sometime in the late 860s.M31, around the time that the Imperium was entering the Eastern Fringe of the galaxy. As they were expanding toward the Halo Stars, they drew the attention of the Rangdan Cerabvores, a mysterious and hostile xenos species who decided to tell these upstart humans to get the fuck off their lawn. Unfortunately for the Imperium, they had the will and the technology to make it happen make a decent attempt at it, and would in fact prove to be the single greatest threat to its existence up until Horus' little temper tantrum.

Information on the Xenocides is scarce, coming from multiple sources and usually only in vague references. This appears to have been intentional, as the Dark Angels deliberately purged all knowledge of the Rangda and the wars fought for the good of the Imperium. No actual images of the Rangda themselves remain, though enough secondary details survived to paint a grim picture: they were lithe yet towering and monstrous in appearance, dangerously intelligent, highly cunning, cruel, ambitious, and technologically advanced. They shared the Imperium's ambition of galactic conquest and were just as determined to seize control of the galaxy. They were also said to be vulpine (fox-like) xenos according to Horus Heresy book 9: Crusade...so basically giant scary space Furries.

The Rangdan Wars, as they are also known, consisted of three separate campaigns: The Conquest of Advex-Mors, the Second Rangdan War, and the Third Rangdan War (also known confusingly as the Rangdan Xenocide).

The first campaign occurred in 839.M30 and focused on the assault and conquest of Advex-Mors by the Dark Angels. This marked the first encounter between the Imperium and the Rangda Empire, and it more or less incited the extreme response that followed. The system was heavily defended, including protection from an armada of Rangdan ships and an orbital war-moon. The latter was able to hold off the combined firepower of three Gloriana-class capital ships (aka the biggest and most powerful warships the Imperium ever produced). In fact, it was so well protected that some mistook it for the Rangdan homeworld. In reality, it was only a minor garrison at the edge of their domain. The fighting was fierce, with the Dark Angels taking more than 10,000 casualties, but this was nothing compared to slaughter that was to come.

The second campaign kicked off in 862.M30 when the Rangdan struck back, plowing into Imperial space with thousands of vessels and more than a dozen war-moons. They attacked from the galactic east and north, overrunning entire worlds and putting the Imperium onto the back foot with shocking speed. Fleet after fleet was lost with all hands, entire Titan Legions were obliterated, and dozens of planets were destroyed as the Cerabvores continued their relentless assault. Eventually, forces from the White Scars and XIXth legions managed to delay the attack long enough for the Imperials to rally and make a stand at the Forge World of Xana II. The siege would be broken after eight months and three thousand dead Astartes when the Dark Angels and Death Guard arrived to counter-attack. But this was only the next step in a war that would last two decades.

The Imperium wound up throwing no less than nine Legiones Astartes at the Cerabvores: the Dark Angels, Space Wolves, War Hounds, Death Guard, White Scars, XIX Legion, the lost XI and II Legions, and eventually the Ghost Legion. Even this wasn't enough, and the destruction continued unabated. The Space Marines committed to the conflict sustained heavy casualties. The Dark Angels especially got their shit kicked in, with one source claiming they were reduced to a tenth of their original strength. Considering the same source lists their overall strength at 100,000 legionaries at the time of the Lion's rediscovery...well you can do the math. By the end of the Xenocides, they had lost their status as the largest Legion to Papa Smurf's blueberries. The Death Guard had to conduct emergency intakes of non-Barbaran recruits just to keep their numbers up, and the II and XI Legions apparently ceased to exist during or shortly after the conflict, hinting that they may have been corrupted or otherwise compromised by the Rangdan and needed to be purged. The Lion received his baptism of fire in the Xenocides, as he had been rediscovered in the midst of the campaign and was almost immediately put in charge of the entire war effort. Despite his sheer Tactical Genius, the bloodshed continued until the climactic battle at Taxal, when more than 300,000 Space Marines were deployed.

Eventually, things got so bad that the Emperor concluded he was going to have to do something incredibly dangerous: open up the Labyrinth of Night and unleash the motherfucking Void Dragon in an effort to break the Rangdan once and for all. Whatever happened, it totally worked and didn't cause a galactic calamity that we know of.

The third and final Rangdan War occurred between 887-890.M30. The numbers are unclear because at this point, the Imperium was more concerned with covering up the truth of how close they had come to a complete loss. Nevertheless, we do know that the Rangdan apparently mounted one last effort to destroy the Imperium. The Dark Angels and Space Wolves were able to turn them back at the staggering cost of 50,000 Astartes. Most of the forces that had fought were sworn to silence, executed, or dispatched to new fronts. A lot of misinformation emerged during this time, with later historians putting their own spin on the conflict. While authorities were busy quarantining planets and downplaying the immense cost of the war, the Rangdan slunk back to their homeworld to rebuild their strength.

When a group of White Scars had managed to locate the Rangda home system after long searching, it became clear that, while broken, the Cerabvores were still a threat too grave to be allowed to endure. With a target now identified, the only thing that was left to be done was for the surviving Rangdan to be slowly, bitterly, painstakingly purged from the galaxy. What followed was a series of "bio-pogroms", a task which fell to the Space Wolves and the Dark Angels, as they were the two Legions the Emperor could most rely on to perform such an ugly and brutal job. This last phase of the conflict took a decade, as the two legions scoured the sector clean of the xenos menace. This earned the Space Wolves their nickname of the "Emperor's Executioners" and the Dark Angel's less well-known, yet equally appropriate nickname of the "Emperor's Exterminators".

Outcome

After the end of the Xenocides, the Dark Angels and the Space Wolves had both been greatly reduced in number, meaning that the progress of the Crusade now rested on the Luna Wolves, Ultramarines, and the other Legions that hadn't been sucked into the meat grinder. The I and VI Legions also became objects of suspicion and fear among ordinary Imperial folk, thanks to the sheer ugliness of the bio-pogroms they'd undertaken (given many of the Rangdan forces were human populations bound with neural shackles). The Ultramarines officially became the largest legion, a status they would maintain throughout the remainder of the Great Crusade and into the Horus Heresy.

The conflict with the Rangdan also spurred the creation of newer and more terrifying weapons of war for the Imperium, most notably the dreaded Psi-Titans of the Ordo Sinister, which were directly inspired by the Rangdan's own superheavy and Titan analogues, the Macrobeests and Osseiovores. The Dark Angels would similarly take lessons from this dreadful war, forming the Order of the Broken Claw (one of many orders within their enigmatic Hekatonystka) to remember the tactics they learned from the xenocides as well as guarding their many treasures.

Wargear and Military Assets

The Rangda made extensive use of slave-soldiers, human as well as xenos. They were controlled through neural collars, which enforced absolute loyalty and reduced the slaves to savage drones. In combat, the Rangda would unleash them in massive hordes in an effort to drown their enemies. During the invasion of Advex-Mors Extremis, a single Randgan Overseer controlled a remote garrison of 10,000 slaves.

In addition to human drones, the Rangda made use of a number of exotic military units about which little is known. These included stalker drones capable of infesting ships in orbit, titanic Macrobeests, super-heavy Osseiovores, and the dreaded Slaugth Murder-Minds (though whether these were allies, drones, slaves, or some kind of bio-construct remains unknown). Based on the Rangdan's reputation for dark science and cunning, it is likely that these were only the most common of the Empire's tools.

While loath to meet foes in direct battle, the Rangda were no slouches and could be deployed in large numbers if needed. Each true Rangda was able to hold their own against a Space Marine in close combat. They employed a number of personal weapons, including lethal personal energy shielding that ignited the air and poisoned blades capable of overwhelming the biology of an Astartes.

The Rangdan fleet was composed of thousands of agile void craft known as war-barques. They employed a form of electromagnetic weapons nicknamed shadow blasters that were capable of both atomising their victims and crippling crews with radiation sickness. However, the true heart of their naval strength were the massive war-moons. These engine of war were crewed by entire detachments of Rangdan warriors and carried enough firepower to match, or overwhelm, an entire Imperial fleet. During the invasion of Advex-Mors, a single war-moon was able to hold its own against three Gloriana-class Battleships, with the Imperium only achieving victory after sacrificing one of these now irreplaceable capital ships.

Trivia

Interestingly, the Xenocides were also the first time Alpharius was heard of, even though the primarch of the XX Legion had yet to be recovered at that point Head of the Hydra reveals this was actually the true Alpharius, just deep undercover and unknown to his brothers. An 'Alpha Legionnaire' gained an audience with the Lion at some point during the campaign, and offered to secretly take over the war so that the Dark Angels could withdraw to Caliban and rebuild their numbers. The end goal, he explained, was to keep the Dark Angels from losing their status as the biggest legion and therefore improve the Lion's chances of someday becoming Warmaster of the Imperial armed forces, the creation of which position both the Lion and Alpharius believed would be inevitable. The Lion turned him down because he was determined to finish what he'd started, which went well for his Legion. And of course he lived to regret this decision as, had he been Warmaster, the Horus Heresy would never have occurred. At very least he could have brought the idea to the Emperor and leaned on Big-E not wanting to lose his gets-shit-done Legion full of Dark Age technology (the only legion with such access and abundance, incidentally).

The mention of Slaugth Murder-Minds as part of the Rangdan forces ties the Xenocides into the 41st Millennium via the xenos species of the same name mentioned in the Dark Heresy RPG. Not surprising, though, since the fluff for the Dark Heresy system and the first several Horus Heresy campaign books were written by Alan Bligh, Emperor rest him.

The names of the some of the Rangdan forces also implies some unpleasant things about their dietary habits, specifically the Cerabvores and Osseiovores. "Cerab" would seem to derive from "cerebrum", the Latin/formal English word for the brain, and Osseio looks an awful lot like "osseous", the Latin word for "bony", which in turn derives from the word "os", meaning "bone". Vore is a suffix meaning "one who eats", deriving from the root word "vorare", "to devour". So, Cerabvore would translate approximately to "one who eats brains", and Osseiovore to "one who eats bones". Given that the Slaugth are also known to eat brains, this suggests they may have gotten it from the Rangdan, or vice versa.

After the end of the Xenocides, the First Legion left a garrison in the Rangdan home system, tasked with guarding the acquired knowledge and relics of the Rangda, just in case some of them had somehow managed to survive the bio-pogroms. The garrison was nearly wiped out at the start of the Horus Heresy by a sneak attack from a Sons of Horus chapter that had come in hopes of looting the place for Rangdan technology to aid them in the war against the Emperor. Though the traitors were initially able to inflict heavy casualties on the defending Dark Angels, that didn't last long, as the Lion's sons then turned around to kill almost 50 Justaerin Terminators and at least three squads of regular Astartes, recapture or destroy most or all of the stolen relics, and generally give the Sons of Horus a well-deserved spanking.

This setup bears similarity to the Guardians of the Covenant, an Unforgiven Chapter known for keeping a great archive in their Fortress-Monastery located on the edge of the Segmentum Pacificus. Coincidentally, one of the Chapter traditions consists of giving a compendium of stories about xenos races annihilated by mankind across the long millennia to their brothers serving in the Deathwatch (for the purpose of uplifting their morale). In the grim darkness of the 41st millennium, memory of these ancient horrors perhaps survives...

If one looks at the Imperium as being basically a copy of Rome (which, honestly, it really is) then the Rangdan Wars can be seen as the Imperium's Punic Wars, right down to there being three of them. Although, it looks that instead of being a republic fighting a series of mercenary-backed trade monarchies with a powerful navy, it was instead a military dictatorship fighting a bunch of aliens who may or may not have used Slaugth mercenaries and had an insanely powerful navy.

tl;dr, it was basically a carbon copy of the Punic Wars.