Miyamoto Musashi (1584-1645), was a Japanese swordsman and ronin. Musashi, as he was often simply known, became renowned through stories of his excellent swordsmanship in numerous duels, even from a very young age. The founder of a style of swordsmanship, he also wrote The Book of Five Rings, a book on strategy, tactics, and philosophy that is still studied today. Miyamoto Musashi is widely considered a Kensei and one of the greatest warriors of all time.