The Brotherhood of the Plague took part in the notorious Bloodpox Campaign in 104.M35, fighting alongside the Death Guard Traitor Legion against the Loyalist Dark Angels Chapter. The twelfth Supreme Grand Master of the Dark Angels Chapter, the esteemed Armaros, contracted the loathsome pox known as Nurgle's Rot.
This resulted in his rapid deformation, and so, Armaros passed on the leadership of the Chapter and voluntarily committed suicide by stepping into The Rock's reactor chamber so as to prevent the contamination from spreading.
The Brotherhood of the Plague warband's colour scheme is not listed in current Imperial records, but as followers of the Plague God, their armour more than likely appears rusty and is marred by decay and putrescence.
The Brotherhood of the Plague Warband's Chapter badge is not listed in current Imperial records.
- Codex: Dark Angels (6th Edition), pg. 23