This book excavates the often neglected role of the Polish government-in-exile within the Allied war crimes trial programme and post-1945 international law. Drawing on newly examined archival sources and biographies of key émigré lawyers, it reveals how Polish and other European jurists helped define the concept of accountability for wartime atrocities long before the Allies convened at Nuremberg. Combining legal and historical approaches, this book traces the Central and Eastern European influences on the UN War Crimes Commission and Allied policy, showing how their ideas about justice, responsibility, victim’s perspective, and law continue to resonate in modern interpretations of the legacy of Nuremberg.