Months of Shame

The Months of Shame was the unofficial name given to a secret, sad, and shameful chapter in Imperial history. It refers to the Inquisition purges that followed the First War for Armageddon in 444.M41, and the violent, months-long confrontation between the Inquisition's Armageddon "containment" task force and the Space Wolves Space Marines, that threatened to erupt into a full-fledged civil war between that Chapter of the Adeptus Astartes and the Inquisition. The internecine hostilities ceased in early 445.M41, following an uneasy truce; however, the larger institutional dispute between the Space Wolves Chapter and the Inquisition remained unresolved.

The Armageddon Containment
The First War for Armageddon in 444.M41 was fought and won for the Imperium under the overall command of the Space Wolves Chapter of Space Marines, and more specifically, their Chapter Master, the Great Wolf Logan Grimnar. The Inquisition, along with a force of Grey Knights, became involved when the nature of the enemy was revealed: millions of Chaos Cultists known as the Children of Sanguinary Unholiness, and a Khornate army of Chaos Space Marines from the World Eaters Traitor Legion led by the Daemon Primarch Angron and his elite guard of 12 Khornate daemons, the Cruor Praetoria. Grimnar, who as Chapter Master knew of the Grey Knights' existence, asked for their help.

A hastily mustered ad hoc Brotherhood of Grey Knights, along with other Inquisition forces and as many as 30 Inquisitors, made swift passage to Armageddon in order to join the ultimately victorious fight. The Inquisition task force was under overall command of Lord Inquisitor Ghesmei Kysnaros. As much as defeating the Archenemy, the Inquisition was there to guarantee that sensitive information regarding the nature of the enemy, and the secret Imperial assets arraigned against it (the Grey Knights in particular, and the Ordo Malleus in general) would not spread beyond the planet.