This volume features 50 documents in Polish, Yiddish, and German, with English translations, exemplifying early Holocaust research undertaken by the Central Jewish Historical Commission in Poland in the years 1944-1949. Featured texts include methodological reflections on how the destruction of European Jews ought to be studied, witness testimonies, and journalistic essays. These writings shed light on the motivations of the commission: commemorating the dead, keeping a historical record of the events, gathering evidence that could be used to bring the perpetrators to justice, working through trauma, loss, and destruction, and providing material for future historical research. The documents are a testimony to the survivors' efforts in using both victim and perpetrator sources to describe the everyday life and death of European Jews under the Nazi regime, while placing the experiences of Jewish communities at the center.