Manachean Commonwealth

The Manachean Commonwealth is a conglomerate of advanced and populated worlds that lies at the border of both the Segmentum Obscurus and the Ultima Segmentum. Established in the early millennia of the Dark Age of Technology, the Commonwealth is first and foremost constituted by the sprawling Hive Worlds of the Manachea System and the neighbouring Imperial Navy Sector Headquarters and fortress of Port Maw. Since the days of the Great Crusade and its liberation from the baleful rule of the xenos empire known as the Mitu Conglomerate, it is arguably the most strategic vital area of the entire Coronid Deeps. By M.30 the Commonwealth was perhaps the premminent power within the Coronid Deeps.This arguably led the Traitor Warmaster Horus Lupercal to personnally lead the conquest of the Manachea-system after his gambit at Istvaan had failed. Suffering harshly under the traitorous regime but ultimately liberated during the Great Scouring, Manachea's position would neverless decline, the once formidable Hive Worlds slowly being surpassed an overshadowed by the growing importance of Port Maw.

History
The Manachea System which lies at the heart of the Commonwealth and which has given its name to the subsector was likely founded during mankind’s first golden age of conquest known as the Dark Age of Technology. The three worlds of Manachea survived the horrors of Old Night relatively intact, its technology still advanced and its disciplined population numbering in the hundreds of millions. However somewhere during the Age of Strife, the system also fell prey to the Mitu Conglomerate, a xenos empire of great strength which ruled by then over much of the Coronid Deeps. The Mitu were a cabal of several psychically empowered pseudo-actinaric xenos species believed to have evolved from a common stock. Technologically advanced and Warp-capable their pocket empire soon grew to subjugate other worlds from whom they periodically demanded a culling of the population and a tribute of flesh to provide them, it was believed, with the basic components to construct their technologies. Although enjoying a semblance of freedom and self-governance, which made their rule less harsh than the brutal slavery maintained by Orks or the Eldar, the Mitu controlled the Manchea System entirely, tracking down and rooting out nascent psykers and forbidding any attempts at space flights. It is unclear how many decades or even centuries the worlds of the future Manachean Commonwealth suffered under that regime, but the overlordship of this vile breed of xenos was brought to an end by the armies of the Great Crusade. The war the Imperium would fight to end the Mitu Conglomerate would be protracted and bloody. Essentially fought as a series of brutal close-quarters boarding engagements in the void interspersed with sudden and world-shattering planetary assaults on both sides, this campaign would mobilize no less than several Expeditionary Fleets, three Legions of the Legiones Astartes – amongst them the Imperial Fists of the Primarch Rogal Dorn – and hundreds of Cohorts of Solar Auxilia. Most of the worlds of the Conglomerate would eventually be purged by Exterminatus, but for the human-populated Manachea-system the Imperium would fight harshly.

For the masses who had lived so long under the oppression of inhuman intelligences and the constant threat of being harvested or culled, Imperial Compliance was taken up with open arms. Due to its long-standing ties and common history, the three inhabited worlds of the Manachea system were established as a commonwealth under the authority of a single Imperial Commander. The seat of power and governance would be on Manachea Vysidae, at Hive Illium where the noble patricians of the Becket would act as Lord Protector of the Manachean Commonwealth. Quickly becoming a powerhouse of military and industrial activity, Manachea prospered serving as a lynchpin of commerce and trade for the entire region. This prominence caused the Commonwealth to become the regional capital of the entire subsector which even adopted its name. At the dawn of the 31st Millennium Manachea was a shining beacon of Imperial civilisation in the northern Imperium, a powerful, autonomous pocket-empire that was utterly loyal its liberators from the Great Crusade and concentrated much of the military might of the Imperium in this region of space.

The Horus Heresy
As a vital and highly industrialized system, it was clear that the Manachean Commonwealth would sooner or later come under the attack of the renegade Warmaster’s troops. However in contrast to the more fractious Cyclops Cluster, the worlds of the Manachean Commonwealth were both better protected and more powerful. On one hand the proximity between the Manachea system and Port Maw meant that the military and naval might possessed by these two worlds would readily be able to support each other and thus posed a threat the Warmaster could not permit himself to ignore. On the other hand, the industrial capacities and primarily the production and reparation capacities of the Port Maw installations constituted an ideal stepping stone for Horus’ March on Terra. Where in the Cyclops Cluster Horus’ armies had benefitted from the element of surprise, this would not be the case at Manachea or indeed Port Maw as several Loyalist survivors, escapees from the Massacre of Istvaan V, had already spread word of Horus’ victory. Worse yet, Port Maw was already rallying every available force to engage Horus’ own war fleets. Fortunately for the Traitors a large amount of its fleet was already engaged elsewhere in a protracted and bloody battle against an ork Space Hulk designated as the Red Polymepheus. Other squadrons had also been dispatched to far-flung sectors under the Warmaster’s orders well before the Istvaan III Atrocity and were struggling to reach their home port when the Warmaster stroke simultaneously at Manachea and Port Maw. History has remembered these troubled times as the Manachean War, Horus having long since planned to weaken the Armada Imperialis battlegroups stationed at Port Maw and had initiated countless schemes and treacheries to ensure that when his axe would fall, it would do so on a weakened and disoriented enemy. The Warmaster’s duplicity would culminate in the Treachery at Port Maw whose outcome would deliver nearly the entire subsector into his hands.