The chapter focuses on the development of the UNWCC from its founding in late 1943 to the summer of 1945. It analyses its position at the nexus of inter-Allied debates on war crimes and demands for post-war justice. The chapter considers the flow of legal ideas through the organisation, and how those ideas, Allied inter-relations and knowledge of war crimes encouraged several representatives at the UNWCC to adopt a more expansive conception of the organisation’s role than that initially conceived by the British Foreign Office.

This chapter introduces the United Nations War Crimes Commission and highlights its significance in relation to debates on war crimes during the Second World War. It is argued that the notion of war crimes at the start of the global conflagation was underdeveloped, and that a range of jurists, some of whom remain little known, made important contributions to developing legal knowledge that helped shape post-war war crimes prosecutions. The chapter explains the book’s focus on Poland and indicates how the Polish engagement with UNWCC can offer a fresh perspective on the emerging Cold War.