Civil wars and intrastate armed conflict are the predominant form of organized violence in the contemporary era. Beyond their direct devastating impact, they fundamentally change societies and are linked to broader global issues and challenges. Taking a thematic approach with a focus on conflict management and peacebuilding, this accessible textbook engages with recent research and comprehensive data to explore the nature of civil war and violent intrastate conflict. With analysis of current and historical conflicts integrated into the chapter coverage, helpful features include boxes highlighting key cases and topics, discussion points opening each chapter, graphs that illustrate important trends, photographs of significant conflicts, suggested readings for each chapter, and a timeline signposting major conflict and security events since 1945. Lecture slides are provided to instructors as an accessible entry point to topics for students from different backgrounds, including those less familiar with data.