This article analyzes the key function of interpreters and translators in a number of war crimes tribunals set up in the British zone of occupation in Germany. Based on archival primary sources, the paper examines the link between legal and military policies and interpreter practices, and raises key questions about institutional language policies. The study of the social positions, identities and cognitive dispositions of interpreters and translators in their relationships with defendants, prosecutors and defenders highlights both the fluidity of their role in that particular situation, and the onerous nature of their task within the process of judgement and punishment of war criminals. The paper contributes to broader discussions regarding the role that interpreters and translators play in situations of conflict. It provides some insight into the highly charged and fluid roles of both the Anglophone and German interpreters and translators who provided the “linguistic presence” of all those involved in the war crimes courts, and it offers a historically grounded analysis of their function in violent conflicts.