Secrets of the Japanese Art of War is Thomas Clearys translation of the seminal writings attributed to Yamamoto Kansuke (1501-1561) on Japanese martial arts and military service. A mysterious man of humble origins, Yamamoto distinguished himself in the service of the redoubtable Takeda Shingen (1521-1573), heir to a long lineage of warriors and renowned for having fought thirty-nine battles without a single defeat. Yamamoto was a career soldier and founder of the so-called School of Certain Victory, from which the famous Miyamoto Musashi (The Book of Five Rings) emerged. His school developed the art of discerning situational combat advantage, so that the attentive warrior or general would commit himself to action only when success was virtually assured.