We are pleased to present the book which – as we believe – will help you deepen your knowledge about the history of Polish Jews during World War II. The book provides crucial information on the Warsaw Ghetto and the Oneg Shabbat group that operated within it and whose founder had been a historian, Dr. Emanuel Ringelblum. His team worked in conspiracy, gathering comprehensive records of the Jewish community’s life and death under the German occupation. While shortly introducing their work, we also care to address several themes related to the fate of Polish Jews during World War II. Therefore, you will find not only the definitions of some key terms and notions, biographical notes, and source texts from the Ringelblum Archive but also a rich illustrative material: photographs and maps. Since 1947, the Emanuel Ringelblum Jewish Historical Institute has been taking care of the unique collection of documents gathered by the Oneg Shabbat that nowadays are called either The Ringelblum Archiveor The Underground Archive of the Warsaw Ghetto. Over decades, the JHI has conducted numerous research projects and has been involved in publishing both academic studies (including the full edition of the Archive) and popular books. It is also actively involved in educational and cultural activities as well as popularizing the knowledge of the Holocaust through organizing exhibitions. We hope that this book will provide you with more information about the history of the Oneg Shabbat clandestine group and allow you to discover how great the importance of the Ringelblum Archive is for the contemporary research on Holocaust. It might also serve as a means to broaden your knowledge of the history presented at the JHI’s headquarters within the permanent exhibition ‘What We’ve Been Unable to Shout Out to the World’.