The Steel Cobras are a Renegade Chapter of Chaos Space Marines of unknown origin and allegiance. The warband was originally Founded as a Chapter of the Space Marines some time during the 23rd Founding in the late 37th or early 38th Millennium.
The Steel Cobras were a formerly Loyalist Chapter of the Adeptus Astartes whose blasphemous worship of the Emperor of Mankind as an animal totem prompted a puritanical Crusade against them by the Ecclesiarchy, led by a particularly bombastic Cardinal. Faced with such an assault by the Imperium, the Steel Cobras turned to the service of Chaos to gain the power needed to defend themselves. They are known to have established a base of operations deep beneath the ammonia seas of the frigid world of Tukaroe VII. Although the Imperium is aware of these Renegades' existence, nothing short of an invasion by an entire Loyalist Space Marine Chapter is considered likely to dislodge them from their fortified seabed bunkers. The only other option is to perform an Exterminatus on the planet, a fate that may still befall Tukaroe VII should the Adeptus Astartes refuse to assault their wayward kin.
The Steel Cobras wear brazen brass coloured Power Armour with dark green trim.
The Steel Cobras do not have their own Chapter badge since they left the service of the Emperor. Instead they wear the usual blasphemous iconography and fetishes associated with the Dark Gods.
- Codex: Space Marines (3rd Edition), pg. 76
- Index Astartes IV, "Rogue Sons - Renegade Space Marine Chapters"