This chapter discusses, first, the relevance of studying the political uses of the past in the context of situations of armed conflict and post-conflict. While “memory politics” occur in everyday political life, these settings are both prone to thorough changes in the collective representations of the past of social groups, but also because the political mobilization of such representations appears to be a major source of legitimation of the use of violence as well as reconciliation efforts. It then introduces the concept of “memory fragmentation”: many existing studies on political uses of the past assume a rather hierarchical relationship between marginal and hegemonic representations of the past, the latter being typically the result of political and institutional uses of the past. By contrast, the concept of memory fragmentation points out that collective memory dynamics have become more diverse and fluid, challenging governments' capability of defining “national” hegemonic frameworks of memory. Furthermore, the chapter presents two analytical dimensions through which memory fragmentation can be usefully analyzed, namely “horizontal” and “vertical” fragmentation. Last but not least, the structure of the volume and the contributions of each of the subsequent chapters are briefly presented.