Crimson Castellans

The Crimson Castellans was a Loyalist Space Marine Chapter of unknown origins and Founding. The Crimson Castelans became embroiled in a civil war between the members of their own Chapter after a portion of their brotherhood turned to Chaos. However, the Chapter, both Loyalist and Renegade factions, was largely destroyed in 993.M41, when the Tyranid Hive Fleet Jormungandr unexpectedly descended upon the world of Sephrax where the Loyalists were battling their Renegade brethren.