Which Japanese swordsman wrote The Book of Five Rings, a classic on strategy?

Miyamoto Musashi wrote The Book of Five Rings, a classic Japanese work on strategy.

Musashi was a swordsman, strategist, painter, and writer who lived during Japan’s transition from the Sengoku period to the early Tokugawa era. His best-known work, Go Rin no Sho, was completed in 1645, shortly before his death. It is organized into five sections named for elements or concepts: Earth, Water, Fire, Wind, and Void.

The book discusses training, timing, perception, battlefield strategy, and the practical use of weapons. Musashi is also traditionally associated with the Niten Ichi-ryū style, which uses a long sword and a short sword together. The Book of Five Rings was written for warriors, not as a general self-help manual, although modern business and leadership writers often adapt its ideas. Legends about Musashi’s many duels are difficult to separate completely from later storytelling.