The Spinward Arm Crusade
The Severan Dominate is a confederation of worlds located just outside the Spinward Arm along the Great Reef, that has seceded from the Imperium of Man under the leadership of the former Sub-sector Governor of the area, Duke Severus XIII of Kulth.
Duke Severus I was unquestionably a hero of the Angevin Crusade that added the Spinward Arm to the Imperium of Man in the 39th Millennium. Without the Rogue Trader’s influence and tactical acumen, the ongoing battles to control the few safe routes through the Reef would have cut the forces inside off from all aid. Some historians even argue that the revered Saint Drusus might not have completed his conquests without the successes of Severus. Of course, it was the Duke’s own failings that let Drusus surpass him. Severus’ greed was his greatest limitation, as he ultimately chose to consolidate his holdings in the cluster just outside the Reef, rather than continue the task of gaining ground inside the Arm.
For generations that followed, the heirs of the Severus family have trod a path based entirely upon lies and loathing. Their resentment built with each generation, as their desire for what was seen as their just reward went ever unfulfilled. Even across the centuries, this unjust fury had few consequences for the Imperium at large, as the descendants of the first Duke Severus descended into a family of marginal influence and power without their Warrant of Trade or the capacity to claim new domains and titles.
In 799.M41, the latest heir to the Severus lineage, Duke Severus XIII, became Lord Sub-sector of the Periphery- the cluster of systems closest to The Serpent’s Trail, one of the two main access points inside the Arm. Even as the local Lord Sector Marius Hax granted him the title, he feared that there might be serious ramifications to the appointment. Hax’s hand, however, was forced in making the selection.
Severus had spent his lifetime establishing a powerful network of allies throughout the Periphery. Key among his allies were a few ranking members of the Adeptus Arbites within the Sector. The Duke used these connections to eliminate any rivals, at the same time as he made certain that his own official records appeared spotless. Recent investigations have brought to light evidence that Severus may have planted witnesses, falsified records, and even sponsored assassinations among some of the most loyal noble families in the Periphery Sub-sector.
Unfortunately, none of these crimes came to light prior to the Duke’s ascension as ruler of the Periphery. Naval forces loyal to him discovered that the storms of the Reef had receded and exposed the path into the Arm once again. Calling troops from all of the worlds under his influence, as well as Xenos mercenaries, the Duke began a campaign to take the worlds of the Arm. Soon, he had influence over a significant number of worlds, inside and outside the Arm, but did not tell Lord Hax that the stars within the Arm were accessible once again.
Disaster struck when the Orks of WAAAGH! Grimtoof descended upon Duke Severus’ holdings. As his holdings began to fall, Severus, out of desperation, turned to the Imperium for aid against the xenos.
The increased Imperial presence inevitably revealed the depths of the Duke’s betrayal. Evidence of his expanded holdings soon surfaced, then the fact that he had begun to send armies into The Arm, long thought lost, and taking planets. Though he had planned to eventually leave the Imperium, the timing forced his hand long before he had completed his preparations. Rather than succumb to the punishments that he so richly deserved, Duke Severus chose to consolidate his forces and secede from the Imperium. Realizing that the paths into the Arm were once again open, Hax petitioned the Lords of Terra for a new Crusade to retake the worlds within, while his own forces fought the Duke’s along the Periphery.