“The Book of Five Rings” was written in the 17th century by Japan’s most famous samurai of all time—“The God of the Sword,” Simmem Musashi-no-Kami Fujiwara-no-Genshin, better known as Miyamoto Musashi (1584?–1645). He was recognized as a legend even during his lifetime. At the end of his path, he became a hermit, settled in a cave, and there wrote his book “Go Rin No Se” (“The Book of Five Rings”). At first glance, it looks like a classic textbook of the main techniques of handling the katana. But at its deepest core, “The Book of Five Rings” is a philosophical treatise—one of the greatest works in history on tactics, strategy, and the philosophy of rivalry. Its principles are applicable in all areas of life, and above all in business. No wonder Musashi’s warrior image is still one of the most popular in novels and films, as well as in computer games. The biographical outline of Miyamoto Musashi is presented by British writer Walter Denning, who lived in Japan in the late 19th century.