The Vastus Sector

In the war-torn galaxy of the 41st Millenium, there are few places that have not been ravaged by war. Over the millennia, countless crusades, campaigns and revolutions have swept through the galaxy, and none of the million worlds of the Imperium have remained untouched by conflict. Each planet has its own litany of conquest, invasion and insurrection, and even during peacetime, the lives of most Imperial citizens remain nasty, brutish and short. The Vastus Sector is, therefore, perhaps a quintessential example of a typical Imperial Sector. Like most Imperial Sectors, it has experienced its fair share of conflict at the hands of traitors, heretics, aliens and zealots.

Geography

The Vastus Sector is an Imperial Sector close to the galactic centre, between the Maelstrom and the Core, in the Ultima Segmentum. It is comprised of around twenty-five thousand stars, of which around six and a half thousand have planetary systems. There are around six hundred and fifty inhabitable worlds, of which one hundred and fifty are within the dominium of the Imperium.

The sector possesses significant levels of key natural resources, including the ore from which Adamantium is refined, as well as significant sources of Promethium. This richness in materials, combined with well-established warp lanes, both for in-sector travel and to neighbouring sectors, mean that Vastus has forever been a battleground between human factions and alien races, competing for control of its material wealth.

History

Evidence of Human colonisation goes back at least 25,000 years. Human settlements had close relationships with Squat clans in the nearby galactic core.

Timeline

M15 - first evidence of colonisation: Early colonies are mining outposts, which ship raw materials back to Terra and to the Squat home worlds. Early colonies appear to have been wiped out: archaeological records contain clear epochs after which no new developments are found until a new period of colonisation began. Exactly what caused the destruction of these colonies remains a mystery.
M25 - Age of Strife: Massive warp storms prevent interstellar travel and bring an end to interstellar human civilisation. Contact with Terra and the Squats is lost, as is most intersector travel. Most worlds sink back into feudal preindustry, although a few maintain basic technology and functioning societies.
M27: a Mechanicum forge ship arrives at Lustrum Furvus and establishes a colony there. Agricultural colonies are established on nearby planets to provide food for the forge workers. Knight households are established on these worlds and swear fealty to the Legio Pantera, the Titan Legion based on the forge world.
M30: the immense warp storms which prevented warp travel are dissipated by the Fall of the Eldar and the birth of Slaanesh, which allows human warp travel to resume. A Mechanicum exploratory fleet from Lustrum Furvus reaches the Squat home worlds and re-establishes contact with Humanity’s closest cousins.
M31 - The Great Crusade: a Blood Angels expeditionary fleet arrives with a Mechanicum contingent. The Lustrum Furvus forge colony, which has become the most powerful system in the sector, joins the crusade to bring the other worlds of the sector into compliance. Squat forces participate in the campaign at the Legio's request. The combined Crusade Fleet achieves many notable victories, most notably expunging the Altovast system of a powerful (but now forgotten) xenos race.
After compliance is achieved, the Blood Angels move on to the next phase of the Crusade. Legio Pantera joins the Crusade and fights with them and with other legions, bringing many new worlds into the Imperium. Several regiments of the Imperial Army are raised, most notably from Procyon XII, the sector’s new capital.
M31 – the Horus Heresy: Several formerly compliant worlds in the sector declare for the Warmaster. The Legio Pantera is dispatched to fortify several systems that stand between the Warmaster and Terra. The Procyon Crusaders are virtually annihilated by Traitor forces on Sicarax IV. Several titans from the Legio Pantera join the defence of Terra.
M32 – the Scouring: After the end of the Heresy, Imperial Guard regiments, supported by Squat forces and Knights, bring the sector back into compliance. Several worlds are subject to Exterminatus due to their populations falling to Chaos.
284.M33 - First Ork Incursion: A large Ork Waagh fleet invades the sector from the Korvus Nebula, which had previously been believed bereft of life. Sector defences are severely diminished due to secondment of Legio Pantera and its Knight support to an Ultramarine campaign to restore Imperial rule over the Cremmlix sector. The greenskin forces conquer nearly forty-five worlds, killing billions, before a massive liberation fleet can be dispatched to cleanse the sector.
539.M33: A chaos cult on Zandriva III overthrows the imperial governor. Before a redemption fleet can arrive, the entire population is sacrificed to the Blood God. The resulting psychic disturbance prevents warp travel in the sector for fifty years, resulting in massive unrest and violence. Eventually Zandriva III is pounded into dust at the orders of the Inquisition to erase the psychic scar caused by the genocide.
976.M34 – the 22nd Founding: The Blood Scorpions chapter is founded using a blend of the gene-seed of the Blood Angels and the Red Scorpions. The Blood Scorpions are established on the death world of Tivon VI, with standing orders to guard the Korvus Nebula and monitor inter- and intra-sector warp lanes.
M36 – the Age of Apostasy: During the reign of Goge Vandire, a number of the sectors Ecclesiarchs establish large power bases and regiments of Frateris Templar. Following the destruction of the main Frateris fleet in the Storm of the Emperor's Wrath, the Blood Scorpions led a crusade to depose the heretic cardinals on Terneth (the sector’s religious capital) and impose the reforms of Sebastian Thor on the Ecclesiarchy.
340.M37: the sector capital is moved from Procyon XII to Aquilius Prime. The resulting loss of revenue from tithes and bureaucratic functions results in a chronic economic depression on Procyon and a rebellion by the poor and dispossessed. The rebellion is brutally put down by General Nikolaus Venator of the Procyon Crusaders: a massive penal legion of almost forty per cent of the Proycon population is raised from the rebels and sent on a penitential crusade on the Eastern Fringe: the legion is never seen or heard from again.
873.M39 - Second Ork Incursion: An immense warband lead by Thrashgut Bedlumm invades the sector. A billion ork boyz supported by a thousand gargants decimate the sector, leaving dozens of worlds in blasted ruin. A two-decade campaign is launched to scour the greenskin from the sector.
124.M40: The Eldar of the Iyanden Craftworld exploit the weakened defences of the sector to invade several planets near the edge of the sector. Claiming that these worlds were once theirs, they evict the populations of these planets and appear to perform elaborate rituals and arcane experiments in dark chambers deep beneath the planet’s surface, before disappearing as quickly as they arrived. The dispossessed population is mind-wiped by the Ordo Xenos to keep information about the Eldar activities secret.
747.M41: a splinter fleet from Hive Fleet Behemoth heads towards to Galactic Core, and annihilates the Squat homeworlds. The tattered remnants of the Squat civilisation flee to Imperial space, including the Vastus Sector. Some are integrated into imperial society, serving as technicians in the Mechanicus, or as auxiliaries in Imperial Guard and PDF regiments. Others become nomads and traders. In the decades following the exodus, the sector is plagued with Tyranid incursions from the former squat home worlds. Hive ships regularly appear in interstellar space lanes, and genestealer infiltration is a major threat to stability. At least one world falls to a genestealer cult, resulting in Exterminatus.
946.M41: contact is lost with two worlds on the periphery of the sector. Immediately prior to the loss of contact, reports are received of the discovery of enormous alien tomb complexes in the remote desert and polar regions. Geological evidence suggests these constructions had previously been buried and had risen from the depths. Inquisition intelligence concludes that these worlds were once tomb worlds of the necrontyr, who are now awaking. Under the command of Lord Inquisitor Halo Macreithe, an expeditionary force consisting of the 3rd, 7th and 9th companies of the Blood Scorpions, the 55th Procyon Crusaders and the titans of the Legio Pantera are sent to secure the perimeter around the silenced worlds.
Shortly after the expeditionary fleet leaves, word is received from a scout ship at the opposite end of the sector: a massive Ork invasion fleet has been spotted heading for Lustrum Furvus...
999.M41: On the far side of the galaxy, Abaddon The Despoiler's 13th Black Crusade reaches and destroys the planet of Cadia, causing the immense Cicatrix Maledictum (or Great Rift) to tear the Imperium apart.

The Vastus Sector, which lies on the edge of the new galactic faultine, is laid waste by warp storms and incursions. The Blood Scorpions struggle to maintain order as warp storms cut off communications and reinforcements, leading to desperate battles against Chaos warbands and Ork invasions. The Procyon Crusaders, now severely depleted, were scattered, fighting defensive actions to protect isolated worlds.

Legio Pantera found itself fragmented, with many of its Titans trapped on isolated worlds. Some engines were lost to the warp, while others held vital defensive positions against Tyranid splinter fleets and emerging Necron tomb worlds. The sector saw a resurgence of Chaos Space Marines, particularly warbands still loyal to Horus’ fallen legions, launching attacks on key planets and attempting to seize the vulnerable sector for the Dark Gods.

Meanwhile, Orks and Tyranids exploited the chaos, launching invasions across multiple systems. Waagh! Griznak ravaged several subsectors on the spinward side, while Tyranid splinter fleets devoured weakened worlds. Necron tomb worlds also began to stir, taking advantage of the warp disruption to reclaim ancient territories. The combination of xenos invasions and Chaos incursions left the Vastus Sector in a state of constant war, with Imperial forces barely managing to hold the line.