Annexation of Nemothil

Annexation of Nemothil was one of the earliest recorded campaigns of the Rebutors Space Marine Chapters (known then as the Lions of Retribution) when they first discovered and claimed the world of Nemothil as their Chapter homeworld, but during their exploration of the planet they were set upon by the treacherous Drukhari. In the end, the Retributors eradicated the xenos menace and claimed the now-uncontested world as their own.

History
"Slay them all! The Emperor demands justice against those who defy his will! No foul alien can stop His fury!"

- Reverend Vies Kughman of the 4th Diocese, invigorating the Lions during their fight with the Dark Eldar pirates on Nemothil

After having roamed the Segmentum Pacificus for a hefty amount of time, the Chapter's Fleet arrived in the Chiros Sector, which at the time had been avoided by delegates of the Imperium. There, the Lions were immediately met with groups of alien pirates. Upon seeing the Fleet, most of these pirates fled. However, a brave band of Drukhari pirates decided to attack the Imperial vessels. These Dark Eldar served a formidable opponent for the newly founded Chapter. Grand Paladin Drehg lead the Redemption into the fray of the battle, bringing down several Dark Eldar fighters. Eventually, the xenos began to board the Battle Barge, placing the loyalists within on the defensive. The Dark Eldar could not dent the morale of the fervent Chapter, and soon they were pushed back from both the Redemption and the Fleet itself.

Upon the retreat of the pirates, Grand Technician Caldean Tavareum analyzed a Drukhari relay message that the Redemption had managed to intercept. The message was promptly shared with the Grand Scholar, who deciphered and translated the alien message; "Return to Nemothil immediately; your mission is futile." Fortunately, the Grand Technician was able to track the location the relay message was sent from; a medium-sized, previously thought uninhabited Feral World. It was assumed the Dark Eldar pirates were establishing a colony upon the planet. Drehg noted how disorganized and crude the Dark Eldar pirates were in combat, and viewed this as a prime opportunity to display the prowess of his new Chapter. Thus, the Fleet ventured to the Fortis System, the location of the planet "Nemothil."

To the surprise of the Chapter, Nemothil stood near a seemingly inactive Warp rift. It was not deemed a concern. Once the Fleet was in high orbit of the planet, three drop pods filled with Scout Marines were deployed. The Scouts were to locate the base of the pirates and signal the Fleet. Then, the Fleet would deploy Space Marines to surround and bombard the area. Soon enough, the Scouts were successful in their endeavor and located a large Drukhari fort. Soon afterward, several squads of the Lions' 4th Diocese led by Reverend Vies Kughman were deployed to surround the base.

As soon as the first bolters were fired, the Drukhari fired back. It was clear that they had been expecting the Space Marines. The assault division landed within the walls of the fort, cleaving the xenos with their chainswords one by one. Grand Paladin Drehg joined the fight, power sword in hand. The aliens put up a fierce fight for the Astartes, and for a short time seemed to hold the upper hand. Yet, despite this, the Lions did not falter. Eventually, the pirates began to flee and disperse. Enraged by this, Drehg ordered the pursuit of the retreating Drukhari, claiming their existence to be against the Emperor's will.

With every last Drukhari on the planet exterminated, Grand Paladin Drehg placed the banner of the Chapter upon the ground, claiming the planet for the Chapter. The planet was renamed Fortis Primaris. Shortly after this, the Fortress-Monastery of Principalis Ultima was built. Humans began to migrate to the planet, and it quickly became an economic hub.