Fellguard Incident

The Fellguard Incident was a massive Imperial excoriation campaign conducted by the Rassian Iron Corps and dozens of other Astra Militarum Regiments in the defence of the fortress world of Kelthorn when it fell into insurrection due to the insidious corruption of Chaos.

Background
The Fortress World of Kelthorn turns to Chaos, and dozens of Imperial Guard regiments are sent to quell the insurrection. The Cadian 39th Regiment assaults the planet's capital city, Fellguard, but are repulsed when daemons rise from the bloody mire to slaughter Guardsman and Chaos Cultist alike. The Rassians are quick to react, grinding the daemonic foe beneath the treads of hundreds of tanks or mowing them down with millions of lasguns.