Among the biggest challenges to peace in the international system, civil wars are the subject of a research program that has burgeoned in the last decades. In this volume, leading scholars introduce readers to theoretical and empirical trends. Part 1 asks, what are the factors bringing about civil wars? The chapters review and point to new frontiers in debates about greed versus grievances, ethnic identities, the role of the state, and transnational dimensions of civil wars. Part 2 addresses how civil wars come to an end, including chapters on third party interventions, mediation, power sharing, peacekeeping, and the societal legacies of wars. The individual chapters also point to what we do not know about civil wars. Part 3 takes a more in-depth look at emerging trends, with chapters on transitional justice and conflict reconciliation, how the status of women may shape both wars and the post-war peace, the link between civil wars and natural resources and environmental factors, as well as data developments that open possibilities for more disaggregated analyses. The wish list for a ‘taking stock volume’ is long, and the editors have done well in presenting a coherent yet diverse set of perspectives. Perhaps missing is due attention to the emerging bodies of work – often based on extensive fieldwork, archival material, surveys, and field experiments – that aim to unpack micro-mechanisms central to conflict dynamics and the development of post-war societies. That said, for students and researchers new to the study of civil wars, the volume promises to be a go-to source for insights into one of today’s central policy challenges.