The introductory chapter presents methodological considerations concerning how to address the issue of forced migrations associated with the loss of territories. Starting with definitions, the chapter attempts to explain why the issue of forced migrations has not been addressed at a pan-European level, from a methodological point of view. It examines academic literature dealing with the issue of the loss associated with forced migrations and underlines the fact that in the last two decades, the research framework has considerably evolved in an attempt to overcome national-centredness. The authors introduce the concept of “politics of history”, which constitutes the core research material of the following chapters focusing on case studies, in an attempt to analyse the legacy of past experiences of the loss in societies and public memory as well as domestic and external policies.