The Mythos Angelica Mortis is a tome of ancient knowledge listing the fraternity of twenty Space Marine Chapters, collectively called the Astartes Praeses, created for the sole purpose of guarding against incursions from within the Eye of Terror following the Great Scouring. By the time of the late 41st Millennium, seventeen remain dedicated to this duty. The Archenemy has annihilated one Chapter and, more shocking still, two others have been branded Excommunicate Traitoris.
Though no comprehensive list has ever been assembled, the current known and past members of the Astartes Praeses include:
| Angels Eradicant | Unknown | Unknown | Unknown |
| Black Consuls | Ultramarines | Second Founding | 31st Millennium |
| Brothers Penitent | Unknown | Unknown | Unknown |
| Crimson Scythes | Unknown | Unknown | Unknown |
| Excoriators | Imperial Fists | Second Founding | 31st Millennium |
| Iron Talons | White Scars | Unknown | Unknown |
| Knights Unyielding | Unknown | Unknown | Unknown |
| Marines Exemplar | Unknown | Unknown | Unknown |
| Night Watch | Unknown | Unknown | Unknown |
| Reclaimers | Unknown | Unknown | Unknown |
| Relictors (declared Excommunicate Traitoris) | Unknown (Presumed to be the Ultramarines and the Dark Angels) | Unknown | Unknown |
| Sons of Malice (declared Excommunicate Traitoris) | Unknown | Unknown | Unknown |
| Subjugators | Imperial Fists | 23rd Founding or 24th Founding | 41st Millennium |
| Viper Legion | Unknown | Unknown | Unknown |
| White Consuls | Ultramarines | Second Founding | 31st Millennium |
Sources[]
- Codex: Eye of Terror (3rd Edition), pg. 16
- Dark Creed (Novel) by Anthony Reynolds, pg. 45
- For The Emperor (Novel) by Sandy Mitchell
- Legion of the Damned (Novel) by Rob Sanders, pg. 14
- Redemption Corps (Novel) by Rob Sanders
- Heroes of the Space Marines (Anthology) - The Labyrinth (Short Story) by Richard Ford