Defence of Acheron

The Defence of Acheron was an Imperial defensive campaign fought by the Imperius Ravagers Space Marine Chapter and local forces of the Acheron System, in defence against encroaching Forces of Chaos, following a large warp surge that engulfed several worlds of the Chapter's home system. This costly campaign ground on for two decades, until the Imperial forces were finally able to eradicate the last remnant of Chaos from their midst, though it cost the Chapter dearly in terms of manpower.

History
A large warp surge comes into being in the Imperius Ravagers' home system of Acheron, engulfing several worlds in its corrupting embrace. Across the Acheron System, nascent psykers and daemons stalk the various worlds as a sudden wave of unholy power ripples through the localised area of warpspace. Those afflicted psykers are either sent irrevocably mad or transfigured into short-lived and murderous demigods who kill thousands and further push those few worlds that remain under civilised control over the brink. The battle to retake these affected worlds by the Imperial forces of the Acheron System is a brutal and deadly affair, as the Imperius Ravagers batter their way into their daemonic foes and their Chaos Cultist allies, blasting apart their bastions and storming their fortresses chamber-by-chamber, leaving bloody abattoirs in their wake. The campaign to eradicate the Forces of Chaos from the system takes two whole decades as the Imperius Ravagers and their Adeptus Mechanicus and Astra Militarum allies do no rest, until every world is cleansed of the vile taint of Chaos. It takes several more decades for the Imperius Ravagers to rebuild their sorely depleted numbers, as they lose nearly half their number during this deadly conflict.