Spinward Front - WAAAGH! Grimtoof: The green-skinned, barbarous Orks have plagued Mankind and the other star-faring species for as long as they has traversed space and it is probable they are Mankind’s oldest xenos foe. The Emperor Himself is said to have fought, and defeated, one of the species’ mightiest leaders during the Great Crusade, averting the rise of an Ork empire that might have grown so powerful as to threaten the Imperium’s manifest destiny to rule the stars. No sector of space is free of their anarchic presence, for they infest the entire galaxy. Ork society, such as it is, is focused on continuing strife, the process of powerful individuals rising to command their own stellar empires pushing the species ever onward. Through ceaseless conflict with themselves and with other species, the Orks spread across entire sectors of space. Once established, they are all but impossible to repulse and so the anarchic, ramshackle Greenskin empires expand across the void, staining vast tracts of the galaxy with their vile presence.The coming of WAAAGH! Grimtoof was a huge shock to the military of the Calixis Sector, for it came from a quadrant of Wilderness Space beyond the Periphery Sub-sector not known to host any such force. The star systems in that region were only partially catalogued and all-but unexplored, but the long range patrols of the Imperial Navy's Battlefleet Calixis should have picked up any nascent threat. If these patrols did detect any such sign, then the intelligence was certainly not acted upon. The Periphery found itself the target of a massive Ork invasion and Severus XIII felt compelled to declare the secession of his worlds and the creation of his Severan Dominate. Some have whispered that the Calixian Lord Sector Marius Hax was, in fact, informed of the oncoming storm, yet chose to withhold the information from Severus, perhaps anticipating, or precipitating in, the Sub-sector prefect’s treachery. Whatever the truth of the matter, it is certain that when WAAAGH! Grimtoof smashed into the worlds beyond the Periphery’s spinward borders, none were in the slightest bit prepared or able to repulse them. Four entire star systems fell in as many months and over a dozen more are now in the grip of total war as the forces of humanity, whether loyal to the Imperium or to the beleaguered Severan Dominate, fight desperately to hold the anarchic xenos foe at bay.Of the first worlds to have fallen to WAAAGH! Grimtoof, very little is known and, while they were ostensibly within the borders of the Dominate, Severus XIII had little or no real power over them. Most exist as names or codes on the stellar charts of the Imperial Navy and may not have known the tread of outsiders for many millennia. The outermost is a dismal world named Deluge, which was host to a small community of mendicant Imperial aesthetes thought to have settled there in the aftermath of the Angevin Crusade. Of the monks’ fate nothing is known, but Deluge has been under the hobnailed heel of Grimtoof Git-Slaver for so long that it is unlikely any are still alive.The world of Porphyry was the second settled planet to fall to WAAAGH! Grimtoof, the Adeptus Mechanicus stripmining facility present there making it a tempting target to the avaricious xenos. The fate of the servants of the Cult Mechanicus remains unknown. Of late, Imperial Navy long range sweeps have detected stray vox signals suggesting some remnant of the Adeptus Mechanicus forces still exist, though in what form none can say. Perhaps it is no more than an automated beacon cycling endlessly into the void, but perhaps it represents a small group that somehow continues to hold out.Between Porphyry and the leading edge of the Ork invasion lies a cluster of worlds linked by minor, barely known and highly unstable Warp routes. Even the largest of these are unexplored and as such have only astrocartographic identifiers, including KW-9 and XD-777. Closest to the border with the Severan Dominate is the world of Augury, a planet long shunned even by the pirates and outcasts that haunt such regions. The Orks took Augury six months into their invasion, but they seem unwilling to commit sufficient forces to keep hold of it and the Severan Dominate has retaken it on several occasions. Currently, Dominate forces have been compelled to vacate Augury by the need to bolster nearby Lukius, and so it nominally falls under those worlds in the thrall of Grimtoof Git-Slaver.Trailing Augury is a line of systems once claimed by the Severan Dominate but currently fighting desperately for their own survival in the face of the xenos invasion. The Imperium is largely unaware and uncaring of their fate and the Dominate is unable to project forces much further than Lukius and Augury. The worlds of Pertinax, Letum, Melqart, and Iris form a lost front, the peoples of each fighting alone to keep the Orks at bay.Several amongst the Spinward Front’s Imperial High Command have proposed sending Imperial Guard and Imperial Navy units to bolster the defence of these beleaguered worlds and in so doing draw Ork forces away from more valuable war zones. Such proposals have met with dogmatic intransigence, for the worlds lie beyond the effective rule of the Imperium. A number of missions have been launched to ascertain how effective such operations might be, but to date they have all met with such overwhelming Ork forces that none have returned with any useful intelligence.