Historians have long understood that books were important to the British army in defining the duties of its officers, regulating tactics, developing the art of war, and recording the history of campaigns and commanders. Now, in this groundbreaking analysis, Ira D. Gruber identifies which among over nine hundred books on war were considered most important by British officers and how those books might have affected the army from one era to another. By examining the preferences of some forty-two officers who served between the War of the Spanish Succession and the French Revolution, Gruber shows that by the middle of the eighteenth century British officers were discriminating in their choices of books on war and, further, that their emerging preference for Continental books affected their understanding of warfare and their conduct of operations in the American Revolution. In their increasing enthusiasm for books on war, Gruber concludes, British officers were laying the foundation for the nineteenth-century professionalization of their nation's officer corps. Gruber's analysis is enhanced with detailed and comprehensive bibliographies and tables.