The Cerulean Guard is a Loyalist Chapter of Space Marines of unknown Founding and origin who fought to defend the Fortress World of Cadia during the climax of the 13th Black Crusade in 999.M41. Little else is currently known about them in Imperial records.
- 13th Black Crusade (999.M41) - The Cerulean Guard deployed a full three companies of the Chapter to aid the high-orbit offensive led by many Chapters of the Adeptus Astartes against the Forces of Chaos during the final battle of Abaddon the Despoiler's 13th Black Crusade just before the fall of Cadia.
The Cerulean Guard's Chapter colours are currently unrecorded in Imperial records.
The Cerulean Guard's Chapter badge is currently unrecorded in Imperial records.
- Warhammer 40,000: Rulebook (8th Edition), pg. 161