Yasan Campaign
The Yasan Campaign was launched by the White Scars' Primarch, Jaghatai Khan, to cleanse the Dark Eldar from the Yasan Sector, in the wake of the Horus Heresy.[1]
With their Primarch at their head, the White Scars efforts to reclaim the Yasan Sector, met with early successes when Jaghatai learned of the Codex Astartes. He would readily agree to splinter his Legion into Chapters, but asked his Successors to fight the Yasan Campaign to its end. Though saddened by the ending of his Legion, Jaghatai was also renewed as the Chapters now acted on their own, allowing the Primarch to pursue his own agenda more fully. He then went on to cleanse many of Yasan's worlds clear of the Imperium's enemies. This included the defeat of the Emperor's Children on Ceobos, the Dark Mechanicum on Aenope and quelling a Mutant uprising on Eoclite. The Dark Eldar however, remained an elusive foe, and it was only after much deliberation that the Primarch discovered a pattern to the Xenos' attacks and knew where to strike next. He then called for reinforcements from the Destroyers, Rampagers and Storm Lords Successor Chapters, before setting course with his fleet to the world Corusil V. It is believed, however, that the Dark Eldar allowed Jaghatai to discover their plans, due to wanting to capture the Primarch and his sons for their twisted experimentations. The White Scars Stormseers say, that Jaghatai knew this, but led the assault nonetheless, as his attack would overcome any of the Dark Eldar's preparations.[1a]
Leading his 1st Brotherhood and their Successors on Corusil V, Jaghatai discovered the Dark Eldar were emerging from a giant Webway Portal located in the depths of the world's forest. It was too dense for the Primarch and his sons to fight from their Jetbikes, and so they began their attack on foot. As they entered the forest Jaghatai and the 1st Brotherhood charged towards the Portal, while the Successors secured their flanks from any ambushes. It was then that the Dark Eldar launched their attack in overwhelming numbers, directed by their Archon, and scores of Jaghatai's sons died horrible deaths or were captured. The Primarch did not waver though and continued his charge towards the Archon who stood in front of the Portal. No matter what foes stepped between them, Jaghatai cut them down and soon the Archon retreated into the safety of the Portal to escape the Primarch's wrath. Jaghatai did not hesitate, though, and charged into the Portal after his foe. The surviving 1sth Brotherhood followed in his wake, but the Portal suddenly closed when the last of them entered it. The Successor Chapters were filled with horror at the apparent loss of their Primarch, but then slaughtered the Dark Eldar that had been left behind by their master. They then spent days scouring Corusil V for Jaghatai and then its System for weeks afterwards, but they could find no trace of him.[1a] Their Primarch's disappearance then caused the White Scars and their Successor Chapters to launch The Hunt of Vengeance, against any Eldar they came across.[1b]
