The Battle of the Penitent took place in 938.M41. The Adepta Sororitas Order of the Ebon Chalice and Order of the Valorous Heart suffer great losses against Warboss Blackaxe's Ork hordes. They are eventually pushed back to the walls of the Cathedral of Saint Dufaux. The attackers are held back only due to the determination and sacrifice of hundreds of Sisters Repentia. They buy enough time for the Battle Sisters to open the vast Cathedral gates, and the greenskins are slaughtered shortly after by two dozen Penitent Engines.