State of War represents a fundamental revision of Japanese history. By illuminating Japan through the lens of war, Thomas Conlan provides insight into how state and society functioned, as opposed to how they were portrayed in ideal. Conlan recreates the experience of war from the perspective of one warrior and then reconstructs how war was fought through statistical analysis of surviving casualty records. State of War also shows that tThe battles of the 14th century mark a watershed in Japanese history. The fiscal exigencies of waging war led to a devolution of political power to the provinces. Furthermore, the outbreak of war caused social status to become performative, based upon the ability to fight autonomously, rather than being prescriptive, or determined by edicts of investiture. TBridging the intellectual gulf between the 14th and 20th centuries, Conlan also explores how the seemingly contradictory categories of "religion" and "war" were integrally related. The 14th-century belief that the outcome of battle was determined by the gods meant that religious institutions warred both ritually and physically, and that religious attitudes frequently underpinned warrior behavior. Based on diverse sources, including documents, picture scrolls, medical and religious texts, and chronicles, State of War rehabilitates warfare as a focal point of historical inquiry and provides a fascinating new overview of premodern Japanese history.