Marie von Clausewitz: The Woman Behind the Making of On War (Oxford University Press, 2016) is an important and fascinating book that not only tells the story of a remarkable woman's life during the tumultuous years of the French Revolution and Restoration. Based on a recently discovered cache of letters between Marie von Clausewitz and her renowned husband, Carl, it also dramatically expands our understanding of the process by which Carl's famous treatise, On War, came to be. Vanya E. Bellinger, currently a visiting professor at the United States Army War College in Carlisle, Pennsylvania, argues that Marie was a crucial foil for the development of Carl's ideas over many years. Marie's connections to the Prussian court (she was born into the prominent von Bruhl family) also helped to secure her husband's often precarious position. Bellinger freely acknowledges Carl's military genius but places Marie alongside her husband as an intellectual partner and political confidante, who played an important role in bringing one of the most famous works of military theory to the world.