Perhaps the most well-known and influential Japanese military manual in Japan and the West was written by an undefeated samurai at the beginning of the Tokugawa Shogunate. Miyamoto Musashi’s The Book of Five Rings or Go Rin No Sho (1643) is an instruction manual on strategy, outlining his philosophy and techniques for achieving victory in combat, emphasizing adaptability and mental clarity. It focuses more on the psychology and philosophical aspects of Japanese swordsmanship rather than an in depth study of martial techniques (he rarely goes into specifics concerning techniques or tactics, instead he focuses on how practitioner should react to given situations).

Right: The samurai Sasaki Kojiro, right, engages Miyamoto Musashi on the shores of Ganryū Island. Panel painting by Japanese artist. Yoshifusa Utagawa (active ca. 1840-1860).

For Musashi martial arts was a means to a spiritual and practical end, the mastery of strategy, which could be accomplished through dedicated study of swordsmanship seen through the prism of Japanese Shinto and Zen Buddhist teachings. Musashi believes mastery of individual combat using the mental techniques in The Book of Five Rings is applicable in combat of any scale, from individual duels (of which Musashi is said to have won sixty and was never defeated) to mass combat between armies.^[1] The Book of Five Rings is centered on single combat or a warrior engaging multiple enemies at one time and there is no specific advice on how to be a great commander of armies like there is in Sunzi’s The Art of War or Kautilya’s Arthashastra.

The Book of Five Rings was written at the beginning of Japan’s early modern era (1600-1868) and after the close of six hundred years of economic competition and internecine warfare among competing samurai houses, major shrines, and temples, all under the auspices of a centralized imperial government with the emperor of figurehead. However, powerful shogunates first the Kamakura (1185-1333) and later the Ashikaga (1336-1573) were favored by the imperial courts. Medieval samurai culture evolved over time but calcified when Japan prepared for two Mongol invasions in the thirteenth century. The reordering of Japanese martial society to meet this foreign threat led to a highly regimented and loyal warrior retainer system, with generations of samurai families serving local daimyos and ultimately shoguns across the Japanese archipelago. During these six hundred years, private wars between competing houses, both secular and religious, were common, with samurai and their religious counterparts pulling from both indigenous Japanese and mainland Chinese military traditions. In the sixteenth century, a new period of civil war erupted, throwing Japan into its own “Warring States” era referred to as the Sengoku era (1467-1568), with a gradual and violent consolidation of territory under unified rule by daimyos Oda Nobunaga (1534-1582), Toyotomi Hideyoshi (1536-1598) and Tokugawa Ieyasu (1542-1616), ultimately resulting in a Tokugawa victory at the battle of Sekigahara in 1600 and a lasting peace.^[2]

Miyamoto Musashi (c.1584-1645 CE) was born around 1584 in Harima province on Honshu, Japan’s largest island, into a family of samurai retainers of the Fujiwara lineage during the end of Japan’s Sengoku era. Trained by his father-figure Shinmen Munisai in Japanese sword fighting at a very early age, Musashi earned a reputation for excellence in swordplay before his twentieth birthday. Musashi found many opportunities to hone his skill as a sword master during his lifetime as he was born during the Japanese unification wars under Oda Nobunaga and later fought in the wars between the Toyotomi and the Tokugawa families in the early sixteenth century during the early Tokugawa Shogunate (1600-1868).  It is believed that he fought in six battles in his lifetime, for both winning and losing sides, and later became a ronin or masterless samurai. Telling us himself in his preface to The Book of Five Rings, “Although I dueled more than sixty times, never once did I lose. That all took place between the time I was thirteen years old and the time I was twenty-nine.”^[3] After his final duel, Musashi abandoned his metal longsword (katana) and short sword (wakizashi) in favor of fighting with two wooden swords (bokken) instead, perfecting a two-sword style called Ni-ten ichi-ryu, or "Two Heavens, One Style.”^[4]  He lived out his final years in a cave on the southern island of Kyushu where he wrote The Book of Five Rings and broadened his artistic pursuits to become a fine calligrapher, sculptor in wood and metalsmith, founding a school of sword guard makers.^[5] As a member of the samurai class, Miyamoto Musashi adhered to bushido, a complex Japanese warrior code that evolved throughout the medieval era in Japan and one that directed the moral and psychological development of the samurai warrior and their training in both martial arts and strategy.  Bushido was a military code strongly informed by both Japanese and Chinese philosophical and religious traditions (Shintoism, Buddhism, Confucianism, and Daoism).^[6] Long a Japanese classic of strategy, the first English translation of The Book of Five Rings did not occur until Victor Harris’ 1974 translation. Victor Harris (1942–2017) was a British scholar, kendo master, and museum curator, where he served as Curator, Assistant Keeper and then Keeper of the Department of Japanese Antiquities at the British Museum.^[7]

Left: This ukiyo-e print depicts Miyamoto Musashi, a renowned Japanese swordsman, philosopher, strategist, and rōnin, famous for his two-sword fighting style and his undefeated record in duels.

The Book of Five Rings is organized into five chapters described by Musashi as “books.” The author maintains that the Way can be shown through an understanding of five different aspects of strategy. He organizes his book using a Zen Buddhist convention, the Go Dai or "Five Greats" — the elements that make up the cosmos: Ground, Water, Fire, Wind and the Void. “The Book of Earth” serves as an introduction that includes a brief autobiography followed by an acknowledgment of the importance of the two mainland philosophies, Confucianism, and Buddhism, to informing the samurai ethic, while also acknowledging the Way (dao) of the warrior is mastery of strategy.

Strategy is the craft of the warrior. Commanders must enact the craft, and troopers should know this Way. There is no warrior in the world today who really understands the Way of strategy. There are various Ways.  There is the Way of salvation by the laws of the Buddha, the Way of Confucius governing the Way of learning. The Way of healing as a doctor, as an artist teaching the way of tea, archery, and many arts and skills.  Each man practices, as he feels inclined. It is said the warrior’s Way is the twofold Way of pen and sword, and he should have a taste of both Ways.  Even if a man has no natural ability he can be warrior by sticking assiduously both divisions of the Way.  Generally speaking, the Way of the warrior is resolute acceptance of death…. By victory gained in crossing swords with individuals, or enjoining battle with large numbers, we can attain power and fame for ourselves or our lord. This is the virtue of strategy.”^[8]

 He follows with a metaphorical discussion on martial arts, leadership, and training as building a house.

The carpenter uses a master plan of the building, and the Way of strategy is similar in that there is a plan of campaign.  If you want to learn the craft of war, ponder over this book. The teacher is a needle, the disciple is a thread.  You must practice constantly. Like the foreman carpenter, the commander must know natural rules, and the rules of the country, and the rules of houses.This is the Way of the foreman….  The foreman should take into account the abilities and limitations of his men, circulating among them and asking nothing unreasonable.  He should know their morale and spirit and encourage them when necessary. This is the same as the principle of strategy.”^[9]

Musashi continues with the description of the outline of The Book of Five Rings and a general description of his fencing style, Ni-ten ichi-ryu, or "Two Heavens, One Style” and the advantages of using two swords, a long sword and a short sword, simultaneously.  

Right: Located in Nishi-ku, Kumamoto, Reigandō “Spirit Rock Cave”) is most famous as the final retreat of Miyamoto Musashi, Japan’s legendary swordsman and strategist. In 1643, Musashi withdrew to this cave to meditate and compose his seminal work, The Book of Five Rings, before passing away in 1645.

“The Book of Water” goes into greater depth concerning  his fencing style, "Two Heavens, One Style.” It describes some basic technique and fundamental principles on kenjutsu or sword fighting, including how to grip the swords, footwork, different kinds of guard, and specifics on five formal sword techniques, including parries and the use of body blows in combat. Moreover, he describes the foundations of a successful warrior, with discussions on the importance of physical presentation or bearing, and the role of sight in situational awareness. Underpinning the chapter are his thoughts on the importance of a proper state of mind before combat.

“In strategy your spiritual bearing must not be any different from normal.  Both in fighting and in everyday life you should be determined through calm.  Meet the situation without tenseness, yet not recklessly, your spirit settled yet unbiased.  Even when your spirit is calm do not let your body relax, and when your body is relaxed do not let your spirit slacken.  Do not let your spirit be influenced by your body, or your body be influenced by your spirit.  Be neither insufficiently spirited nor over spirited.  An elevated spirit is weak, and a low spirit is weak.  Do not let the enemy see your spirit. 

Small people must be completely familiar with the spirit of large people, and large people must be familiar with the spirit of small people.  Whatever your size, do not be misled by the reactions of your own body.  With your spirit open and un-constricted, look at things from a point of view.  You must cultivate your wisdom and spirit.  Polisher wisdom: learn from justice, distinguish between good and evil, study the Ways of different arts, one by one.  When you cannot be deceived by men you will have realized the wisdom of strategy.”

The wisdom of strategy is different from other things.  On the battlefield, even when you are hard-pressed, you should ceaselessly research the principles of strategy so that you can develop a steady spirit.”^[10]

Musashi’s next book, “The Book of Fire,” focuses on fighting, specifically, the challenges faced by a warrior in the heat of a larger battle engagement and the importance of timing to victory. He begins the section by stating “In my strategy, the training for killing enemies is by way of many contests, fighting for survival, discovering the meaning of life and death, learning the Way of the sword, judging the strength of attacks and understanding the Way of the “edge and ridge” of the sword.”^[11] Three major themes of the chapter include awareness and adaptability, the importance of seizing and maintaining the initiative, and identifying the scope of the battle and applying different strategies depending on the tactical circumstance (single combat versus mass combat). 

Left: Japan in Provinces in the time of Tokugawa Ieyasu (1542-1651. Scan of plate facing page 2 of "A History of Japan during the century of early foreign intercourse (1542-1651)", by Murdoch and Yamagata.

The opening passage of “The Book of Wind” contains the essence of the section; “In strategy you must know the ways of other schools, so I have written about various other traditions of strategy in this Wind Book. Without knowledge of the Ways of other schools, it is difficult to understand the essence of my Ichi school.”^[12] Here, he discusses what he considers to be the failings of various contemporary Japanese fighting styles, critiquing how other fencing schools approach the use of long and short swords through an analysis of cuts and parries, focus to obtain situational awareness, footwork, and the use of speed or tempo in fencing. “The Book of Wind” stresses the importance of understanding the military philosophy and practices of your opponents as a necessary ingredient for victory.

“The Book of the Void” (sometimes translated as “Emptiness”) describes on one short page his thoughts on consciousness and the role of nature as teacher. In this final meditation, both his Zen Buddhist and Daoist influences shine through. 

To attain the Way of strategy as a warrior, you must study fully other martial arts and not deviate even a little from the Way of the warrior.  With your spirit settled, accumulate practice day by day, and hour by hour.  Polish the twofold spirit, heart and mind, and sharpen the twofold gaze perception and sight.  When your spirit is not in the least clouded, when the clouds of bewilderment clear away, there is the true void .”^[13]

Miyamoto Musashi died in 1645 in a cave on the island of Kyushu. Musashi's death signaled the passing of the great “Age of Samurai” when open-dueling and clan warfare was an accepted part of Japanese culture.  Under the Tokugawa Shogunate, Japan entered a prolonged period of peace and stability that witnessed the defeat of the last Ashikaga rebels and the closing of Japan to most Western influences (the Dutch did maintain a trading outpost in Nagasaki harbor). For the next two and a half centuries, Japan's samurai would continue to practice their martial arts in their schools, but their main purpose, soldiers in the service of daimyos, would virtually disappear during the Tokugawa era, while the rise of Japan's merchant class in the eighteenth and early nineteenth centuries undermined the traditional power of the samurai. Without a well-defined role in Japanese society, samurai training and customs atrophied. However, Japan's interest in its samurai heritage would be rekindled in the late nineteenth and early twentieth century with the rise of a militaristic Imperial Japan. Japanese officers, now carrying their family swords into battle in Korea, Manchuria, China, and Southeast Asia, resurrected the ideals and practices of the samurai. With the Allied defeat and occupation of Imperial Japan at the end of World War II, Japan was forced to reorder its society, moving from militarism to capitalism as its main endeavor. Modern Japan's rise to the second most powerful economy in the world for decades is in no small part due to its mastery of economic strategy, a strategy informed by the writings and wisdom of Miyamoto Musashi’s treatise. 

 Footnotes 

[1]  For more on Miyamoto Musashi’s duels, see Stephen Turnbull, The Lone Samurai and The Martial Arts (Arms and Armour Press, 1993), 66-69.

[2]  For an excellent brief overview of medieval Japanese military history, see Thomas Cleary’s The Japanese Art of War: Understanding the Culture of Strategy (Shambhala, 1992), 3-11. For an in-depth treatment of samurai culture, see Stephen Turnbull’s landmark study in English, The Samurai: A Military History (Routledge, 1996).

[3]  Miyamoto Musashi,  The Book of Five Rings, trans. Thomas Cleary (Shambhala, 1993), 3.

[4]   “Niten Ichi-Ryu: The Ancient Two Sword school of Minamoto Musashi,” Dento Kobudo Kai

Traditional Old Martial Arts Club, https://www.dentokobudokai.co.uk/karate-styles/niten-ichi-ryu/, accessed 4/17/2025. 

[5]  Winston L. King, Zen and the Way of the Sword: Arming the Samurai Psyche (Oxford University Press, 1993), 7-32, 114-115.

[6]  See King, Zen and the Way of the Sword: Arming the Samurai Psyche, 123-156, for a detailed discussion on the religious and cultural underpinnings of the Japanese Bushido code.

[7]  Victor Harris Obituary (1942-2017) https://www.onohaittoryubook.com/home/acknowledgements

[8]  Miyamoto Musashi, A Book of Five Rings: A Guide to Strategy, trans, Victor Harris (Overlook Press, 1974), 37-38. 

[9]  Ibid, 41-42.

[10]  Ibid, 53. 

[11]  Ibid, 69.

[12]  Ibid, 85.

[13]  Ibid, 95. 

Primary Source Bibliography 

Miyamoto Musashi. A Book of Five Rings: A Guide to Strategy. Translated by Victor Harris. Overlook Press, 1974. 

_____. The Book of Five Rings. Translated by Thomas Cleary. Shambhala, 1993. 

Secondary Source Bibliography 

Cleary, Thomas. The Japanese Art of War: Understanding the Culture of Strategy. Shambhala, 1992. 

King, Winston L. Zen and the Way of the Sword: Arming the Samurai Psyche. Oxford University Press, 1993. 

“Niten Ichi-Ryu: The Ancient Two Sword school of Minamoto Musashi.” Dento Kobudo Kai Traditional Old Martial Arts Club. https://www.dentokobudokai.co.uk/karate-styles/niten-ichi-ryu/

Turnbull, Stephen. The Lone Samurai and The Martial Arts. Arms and Armour Press, 1993.