War on Hylas ends with Imperial Victory

The long war on Hylas finally came to an end in 03.018M42, after continuing on and off since the ork invasion of 012M42. The war had been long and hard for both sides, and the orks had come close to total victory, prior to the coming of the Cicatrix Maledictum. With the catastrophe of the warp bringing unending war to the Vork Ork Expanse, much of the greenskin interest in Hylas waned, allowing General Van Dorn to dig in and begin to retake much of the lost territory.

However, Van Dorn was similarly cut off from the Imperium, but the arrival of Crusade forces from and re-establishment of contact with the Imperial base at Bastien allowed the Imperium to shuttle fresh reinforcements to the Hylas battlezone.

The Sky Lords arrived in early 03.018M42, and with Van Dorn planned the final stages of the total annihilation of the Orks on Hylas. Assaulting Tennyson, the Sky Lords managed to ambush the Orks as they came out to fight, and despite aggressive assaults by the greenskins, the Sky Lords' heavy armour and air superiority ensured that there was no real hope of an Ork victory.

Tennyson fell on 1003.018M42, with the Imperial Guard mopping up the rest of the greenskins in the subsequent months. Hylas would take years to recover from the long war, perhaps decades, but the Imperium had managed to hold on to their last few possessions in the Zadoc subsector, a tenuous Imperial possession surrounded on all sides by hostile forces.