People in prison are usually (and often exclusively) seen and approached as persons who have committed one or more crimes and who have to pay their debt to society. However, while in prison, they often get victimised themselves. Research has demonstrated that prisons tend to be unsafe environments where various forms of victimisation take place. These forms of victimisation often go unnoticed and usually do not attract much interest from policymakers or society at large: prisoners are, indeed, far from ‘ideal victims’. This book is devoted to understanding prisoner victimisation, in particular from a European perspective. Chapters in this volume focus on recent empirical work in a number of European countries (Belgium, England and Wales and the Netherlands). These chapters are complemented with a series of reflections from a conceptual, methodological and human rights perspective. Chapter “The Victim-Offender Overlap in Prisons and Associated Challenges for Prison Managers” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.