Hall challenges several assumptions in Athe gunpowder revolution@ and Athe military revolution@ of the sixteenth century. He sees improvements in the manufacture of gunpowder as the key element in allowing artillery to live up to some its early promise. However, the first impact on battle was to reemphasize the role of cavalry, not eliminate it. After intial success in sieges, firearms later proved more effective in defensive situations. This led to an increase in fortified sites, which required larger armies to garrison them. Only large states could afford the larger armies. Hence, Hall argues, artillery changed warfare, but not in the ways we have come to think and not in a steady, incremental manner; the major changes appeared only in the seventeenth century. This is a complex study of western land warfare that combines information from recent studies on military technology with the author=s own discoveries and analysis. It is a detailed study of artillery, infantry and cavalry weapons, and the use of combined arms that will be read carefully by specialists in military history.