Battle Sisters are recruited solely from the female progena of the Schola Progenia facilities spread across the galaxy. They are orphans of the Imperial servants who have given their lives in the service of the Imperium. While being raised within the Schola they receive a strong Ecclesiarchal upbringing and education, coming to regard the Emperor as their spiritual father. Progena recruited into the Sisterhood are indoctrinated even further into the Imperial Cult, becoming even more fiercely devoted to the Emperor and the Imperial cause. Their duty as part of the Sisterhood is to ensure and enforce the physical and spiritual purity of humanity and the departments of the Adeptus Terra. As they frequently share the same role as the Ordo Hereticus, Battle Sisters often form a major part of Ordo Hereticus forces.
The standard weapon of Battle Sisters are usually Godwyn-De’az Pattern Boltguns, though others frequently carry Bolt Pistols and close combat weapons such as Chainswords. For personal protection, Battle Sisters wear specialized Power Armour.