- "The worst enemies are those we make ourselves."
- — Imperial Thought For the Day
Excommunicate Traitoris is a High Gothic bureaucratic designation that represents the highest form of Imperial reproach against an Imperial citizen or organisation that has committed extreme acts of heresy against the Imperium of Man, including mutation, rebellion and corruption by Chaos. It is the ultimate form of censure: a Traitor is officially banished from the Imperium on pain of death and cast from the light of the benevolence of the Emperor of Mankind. There is no graver fate for those that serve the Imperium. When an individual or organisation is declared Excommunicate Traitoris by either the High Lords of Terra or an Inquisitor of the Ordos of the Inquisition, the accused is struck from the annals of Imperial history. Their names are deleted from the scrolls of honour in the Hall of Heroes in the Imperial Palace and wiped from the memories of the Librarium Terra's databases and other Imperial archives by the Deletions Teams of the Administratum's Historical Revision Unit. If the accused is an individual Astartes or an entire Chapter of Space Marines, the gene-seed stores from that Chapter held by the Adeptus Mechanicus will be destroyed and if any of the Traitor Astartes are slain, their bodies will be incinerated so that their blood will no longer taint Mankind. However, if an accused Heretic confesses their sins against the Emperor and repents their misdeeds, their deaths are quick and clean. But more often than not, the accused Traitors flee for their lives, usually towards the hell-storms of the great Warp rift in the Segmentum Obscurus known as the Eye of Terror. With no sanctuary to be found within the realms of Man, they will be forever hunted for the rest of their days or executed on sight by any and all loyal servants of the Imperium.
- Codex Imperialis (2nd Edition)
- Dark Heresy: Core Rulebook (RPG), pp. 226, 267
- Dark Heresy: Ascension (RPG), pg. 119
- Dark Heresy: The Radical's Handbook (RPG), pp. 225-226
- Bleeding Chalice (Novel) by Ben Counter
- Inquisitor (re-released as Draco) (Novel) by Ian Watson