This book offers the first comprehensive legal analysis and empirical study of accountability concerning the EU’s peacebuilding endeavours—also referred to as civilian crisis management. Since 2003, the EU has launched more than twenty civilian missions under the CSDP in conflict-torn regions in Eastern Europe, the Western Balkan, sub-Saharan Africa, the Middle East, and South East Asia with the aim of restoring stability and security. Mission mandates cover a broad range of multidimensional tasks, such as border monitoring, rule of law support, police training, law enforcement capacity building, and security sector reform. In light of these numbers and tasks and given (recent) alarming insights from practice, it begs the question who is accountable (to whom) for the EU’s manifold extraterritorial peacebuilding activities. With a view to answering this question, this book combines tools of legal scholarship with insights from political science research, both in analytical and conceptual terms. The thorough analysis of the law and practice of political, legal, and administrative accountability in civilian CSDP leads to the following conclusion: when scrutinizing the institutional and procedural framework set out by law, the accountability assessment is sobering, but when approaching it from a practice angle, the verdict is promising—in particular as regards accountability at the EU level.