The Thirty Years' War (1618-1648) was one of the longest and bloodiest wars in world history. This new introduction clearly outlines the central political decisions and key military events. It particularly examines the causes of the war, discusses the question of blame, and traces the long path to peace. The narrative also addresses how people at that time managed to make sense of their circumstances and maintain their mental well-being. Concise overviews of important military events alternate with detailed explorations that inform about the warfare of the time, the role of mercenary armies, and the impact on the civilian population.