During wartime, the violent use of war captives for sex was not considered criminal rape. Mass rape was one of the acts of punitive violence during the sack of a city, but if the siege had ended through diplomatic negotiations rather than storming the walls, by custom the inhabitants were neither enslaved nor subjected to personal violence. Mass rape occurred in some circumstances, and is likely to be underreported in the surviving sources, but was not a deliberate or pervasive strategy for controlling a population. An ethical ideal of sexual self-control among enlisted men was vital to preserving peace once hostilities ceased. In territories and provinces brought under treaty with Rome, soldiers who committed rape against the local people might be subjected to harsher punishments than civilians. Sertorius, the long-time governor of Roman Spain whose policies emphasized respect and cooperation with provincials, executed an entire cohort when a single soldier had attempted to rape a local woman. Mass rape seems to have been more common as a punitive measure during Roman civil wars than abroad.