Maeleum Datum : 999.M34
Since the Proclamation of Horus, the Imperium had faced tens of thousands of planet-scale rebellions, and more smaller uprisings than even the scribes of the Administratum could keep count of. The Traitor Legions and other renegade factions in the Eye of Terror sponsored and manipulated these revolts, spreading lies and cultivating anger against the Imperium before providing the tools with which (so they claimed) the oppressors could be overthrown.
For over three thousand years, the Ordo Hereticus had led the Imperial efforts to uncover rebellious plots and crush them before they could reach fruition. For every rebellion that had unfolded, there was at least one other which the Sigillite's heirs had prevented. But as the end of the thirty-fifth millennium drew nigh, so did the greatest failure of the Inquisition.
Individual worlds had broken free of the Imperium before, as had star systems, clusters, and even whole Sectors. This time, however, an entire Segmentum was about to declare its independence from Holy Terra. During the last decades, the worlds of Segmentum Pacificus had suffered from increased xenos raids, as Ork forces and Dark Eldar warbands preyed upon isolated worlds, the later departing long before the Imperium could respond.
On the world of Nova Terra, a conclave of the Segmentum's mightiest, most influential individuals declared themselves as the Ur-Council, and announced that they had rejected the corrupt rule of the Imperium. They phrased their rebellion very carefully, not outright denouncing the God-Emperor but instead those who claimed to rule in His stead : the High Lords of Terra, whom they accused of being self-indulgent petty tyrants who saw the human race as nothing but a resource to use in their own little games of power.
All across the Segmentum, Imperial representatives turned their coat or were eliminated. Tens of thousands of worlds declared their independence from the Imperium. Their motivations and rhetoric varied wildly, but at its core was the same anti-Imperial sentiment. In their view, the Imperium had failed Humanity : it did not protect the species, but enslaved it, crushing it underfoot to fuel its own existence regardless of the suffering caused in the process.
Even the forge-worlds of Pacificus were affected by the spreading of rebellious ideas, despite the Mechanicus' ruthless methods of control. The Prophet of Cogs had remained in hiding, but had also sent emissaries from their secret redoubt, tasked with offering their knowledge freely to all who may use it to benefit Mankind as well as help their brethren enslaved to the Cult Mechanicus see the truth of their condition. When the Ur-Council made their declaration, they seized the opportunity, rising up against their superiors in the Mechanicus' byzantine hierarchy. Scores of forge-worlds were ravaged in the ensuing conflicts, much to the Prophet of Cogs' horror, whose agents worked tirelessly to rescue those who could still be saved from the devastation.
Still, not all of Pacificus was part of this rebellion. Entire Sectors remained steadfast in their devotion to the Golden Throne, while worlds surrounded by rebels clung to their loyalty. The Cardinal and Shrine worlds of the Ecclesiarchy had been spared from the worsening conditions of the Segmentum, protected as they were by the immense armies of the Faithful, and their leaders vehemently proclaimed their utter and eternal dedication to Him on Earth. Those cults and rebellions which had been fostered there were crushed utterly, only for images of the brutality of these crackdowns to be diffused to neighbouring systems, that they may witness the true face of the Imperial 'Faith'.
All of this was the result of centuries of preparation, a colossal undertaking that had required the cooperation of several Traitor Legions, under the ultimate direction of Horus Lupercal himself. The Arch-Traitor had allied with the ever-elusive Alpha Legion in order to orchestrate the rise of the Ur-Council and the secession of Segmentum Pacificus. Night Lords warbands had fanned the flames of fear and discontent by launching carefully targeted raids that left only atrocity and death in their wake, with no trace of the identity of those responsible. Infiltrators had redirected supplies and lost relief forces under the guise of the Administratum's usual incompetence. Members of the Inquisition had been drawn into labyrinthine webs of intrigue that ultimately led nowhere, with hundreds of them being killed within weeks of the Ur-Council's proclamation by Horusian kill-teams, their deaths arranged to further fuel rebellion against the Imperium by shattering the image of invincibility the Ordos took great pains to project.
This did not mean that the Prince of the Eye now had control of the Segmentum : in truth, he didn't even control the Ur-Council. While the Horusians and Alpha Legionnaires had agents in the Ur-Council and hooks in many more of its members, they were vastly outnumbered, and kept their true allegiances secret.
The purpose of this great rebellion, which only the Heresy itself had ever surpassed in scope in the history of the Imperium, was not to create a new fiefdom for Chaos outside the Eye of Terror. It was to put the High Lords into a position where no matter what they did, they would lose.
When word of the Ur-Council's actions and the situation in Pacificus reached Terra, the prevalent reaction was shock, promptly followed by apoplectic fury. The High Lords sent mustering orders across the entire Imperium, and gathered a fleet such as the galaxy hadn't seen in generations in order to reclaim Segmentum Pacificus. Hundreds of billions of Imperial Guardsmen, tens of thousands of Navy ships, and thousands of Space Marines from several Legions were assembled, along with the greatest Mechanicus armada seen since the days of the Great Crusade.
The new Fabricator-General of Mars, who had ascended to the position following the political nightmare that had been the Prophet of Cogs' unleashing of the cyberghoul hordes and successful escape, was convinced that the one the Parliament of Mars had proclaimed an arch-heretek was behind the uprising of Pacificus. He was wrong : the Prophet had remained untouched by the whispers of Chaos, focusing instead on wielding the pure, untainted fires of Science and Reason to build up a small but prosperous – and more importantly, growing – utopia far from the Imperium's eyes.
Alongside these military forces were veritable hordes of the Ecclesiarchy's faithful, whose numbers surpassed all the rest of the Crusade combined but whose fighting potential only equalled a fraction. The Space Marine commanders who had claimed overall command of the Crusade regarded them as little more than burdens on their logistics, but the politics of the Imperium meant they couldn't simply send them away – not to mention the fact most would have died of starvation long before returning to their homeworlds.
Plans were drawn for the reclamation of Segmentum Pacificus. The Astartes believed that a strike in depth, directly on Nova Terra and the heretical Ur-Council that had risen there, would shatter the morale and organization of the rebels. From there, they would then be able to strike at the other cores of resistance, crushing them one by one so that the diplomats could convince other worlds of the wisdom of returning to the Emperor's benevolent embrace.
That plan wouldn't have been quick : it was estimated that the reclamation of Pacificus would last for decades, if not centuries. But before the Crusade could even begin, the powers that had manipulated the Segmentum's rebellion from the shadows made their move. Potent rituals were performed in the Eye of Terror and beyond, with great sacrifices of blood and souls offerred up to the Primordial Annihilator under the patronage of Horus himself.
The Warp flared all across Segmentum Obscurus, causing cults of Chaos to rise up in rebellion. Most of them were aligned with Khorne, and summoned daemonic hosts along with World Eater Chaos Marines, threatening to drown the Segmentum in blood. Only Space Marines could hope to stand against these foes, and the vast contingents of Astartes who had been gathered to lead the reclamation crusade of Pacificus were diverted, along with billions of Guardsmen and Mechanicus engines, to defend against this new threat.
With their departure, command of the Imperial reclamation campaign passed into the hands of Imperial Guard officers and Puritan Inquisitors, whose approach to the Pacificus Rebellion could best be summarized as 'extreme'. Fanatical devotees of the Imperial Creed, they saw the rebellion of Pacificus as an insult to the God-Emperor, and the entire Segmentum as tainted by Horusian ideals that would inevitably drown this part of the galaxy in madness and ruin if left unchecked. In their eyes, save for those few loyalist enclaves that remained, the entire Segmentum needed to be cleansed with fire, and they didn't hesitate in the application of the flame.
From the onset of the crusade, entire hives were razed from orbit, and the Exterminatus sanction was deployed on a dozen worlds. On planets whose infrastructure required a more subtle approach, hosts of Guardsmen and fanatics hundreds of millions strong were deployed, with orders to wipe out the population completely so that new colonists could be brought in. Their minds filled with speeches about the threat of heresy, the men and women of the Astra Militarum performed their grim duty, those who dared question their orders executed on the spot by their Commissars.
If the Imperial high command hoped to crush the spirit of the rebels with these displays of ruthlessness, it was soon disappointed. Horusian propaganda ensured that the rebels didn't see the wrath of the Imperium as something to be appeased through surrender and submission, but something to be defied. Public broadcasts denounced the Imperial atrocities, and claimed that all the people of Pacificus were in danger should the False Emperor's bloodthirsty servants not be stopped. Meanwhile, the leaders knew that, even if their people were 'only' purged and subjected to even greater oppression should they surrender, their own fates would be unspeakably worse.
Whether due to devotion to their people, true belief in the cause of freedom, or craven fear for their own hide, the leaders of Pacificus' border systems refused to kneel again, no matter the cost. Faced with the might of the Imperial warmachine, they swiftly became desperate, and searched for any method by which the invaders could be fought back. The Dark God Nurgle seized this opportunity, whispering terrible secrets into the minds of researchers working themselves to death to find some way to save their people from extermination. The Lord of Plague gave them the means to save their people from death itself, ensuring that their worlds would never be claimed by the Imperium.
Faced with the desolation of their worlds, the leaders of twenty-one rebellious systems unleashed a weapon that was a mix of sorcery and biology, determined to deny the Imperium victory. A terrible pestilence swept across their worlds, killing all it infected, rebels and loyalists alike – and then raising them anew as living dead, their souls trapped within their rotting bodies, their horror and despair creating powerful Warp Storms that kept the Imperium from blasting the infected worlds into oblivion with their fleets' firepower.
Some few were blessed with keeping their mental faculties, gaining great psychic powers from Grandfather Nurgle and leading the teeming undead hordes into rebuilding their worlds into something more pleasing to the God of Decay who had delivered them. Plague Marines of the Death Guard began to appear, summoned from the Eye of Terror by the undead lords, and swarms of Nurglite daemons manifested on those infected worlds that slipped ever closer to the Warp itself.
The Kingdoms of the Dead now stood between the Imperium and the rest of Pacificus, blocking the most direct roads to the Segmentum. Many Warp paths remained, of course, for such is the scale of the galaxy that even a thousand blockaded stars couldn't truly block all passages, but the Imperial advance slowed to a crawl. The rebels saw the Kingdoms as the result of uncontrolled biological weapons, blaming it on the Imperium (a claim made all the more believable by the use of the Life-Eater virus by the Inquisition on several condemned worlds prior to Nurgle's interference). A quarantine was imposed, with any ship arriving from the Kingdoms being immediately destroyed lest it bring the plague with it, and the rebel leaders swore that the death of the Kingdoms' populations would not go unavenged.
News of the Imperial crimes and defeats were also spread throughout the rest of the Imperium, causing a surge in rebellions that ultimately led to the dismissal and replacement of high command in Pacificus. Reclaiming the Segmentum was still a priority, but not only would current methods only reclaim a graveyard, the cost of the campaign might very well break the Imperium itself if things continued as they were. The scorched-earth policies were abandoned in favor of more conventional conquest and subjugation, but the harm had already been done : none of the rebellious principalities of Pacificus would accept peaceful reintegration in the Imperium.
A protracted and bloody conflict was inevitable, and the Lord Inquisitors of the Ordo Hereticus feared that, by the very action of fighting it in the first place, they had already fallen into the Archenemy's trap.
AN : Glad to see you enjoyed the Prophet of Cogs. As you can see, they are still kicking, and we are going to see more of them.
There is very little lore about the Ur-Council of Nova Terra. You would think that an entire Segmentum seceding from the Imperium for almost a thousand years would deserve some detail, but no. Perhaps we will learn more of the Interreignum someday, but I doubt it - it's likely to be just one more mystery left in the distant past, which to be fair does serve a purpose in establishing the age and ignorance of the Imperium in the 'modern' era.
The next chapter will still be focused on the events of Segmentum Pacificus. I am planning to write a description of the small kingdoms that have risen from the collapse of the Segmentum, so if you have any suggestions for technologies, philosophies, political systems, etc, please tell me in your review !
Zahariel out.