I have trained in the way of strategy since my youth, and at the age of thirteen I fought a duel for the first time. My opponent was called Arima Kihei, a sword adept of the Shinto ryū, and I defeated him. At the age of sixteen I defeated a powerful adept by the name of Akiyama, who came from Tajima Province. At the age of twenty-one I went up to Kyōtō and fought duels with several adepts of the sword from famous schools, but I never lost.— Miyamoto Musashi, Go Rin No Sho
Munisai's tomb says he died in 1580, which conflicts with the commonly accepted birth date of 1584 for Musashi. Further confounding his birthdate, the genealogy of the extant Miyamoto family recounts Musashi was born in 1582. Kenji Tokitsu has suggested that the accepted birth date of 1584 for Musashi is wrong, as it is primarily based on a literal reading of the introduction to The Book of Five Rings where Musashi states that the years of his life "add up to 60" (yielding the twelfth year of the Tensho era, or 1584, when working backwards from the well-documented date of composition), when it should be taken in a more literary and imprecise sense, indicating not a specific age but merely that Musashi was in his sixties when he wrote it.
The details of Miyamoto Musashi's early life are difficult to verify. Musashi himself simply states in The Book of Five Rings that he was born in Harima Province. Niten Ki (an early biography of Musashi) supports the theory that Musashi was born in 1584: "[He] was born in Banshū, in Tenshō 12 , the Year of the Monkey." The Historian Kamiko Tadashi, commenting on Musashi's text, notes: "Munisai was Musashi's father ... he lived in Miyamoto village, in the Yoshino district [of Mimasaka Province]. Musashi was most probably born here." His childhood name was bennosuke (弁之助).
Regardless of the truth about Musashi's ancestry, when Musashi was seven years old, the boy was raised by his uncle, Dorinbo (or Dorin), in Shoreian temple, three kilometers (~1.8 mi.) from Hirafuku. Both Dorin and Tasumi, Musashi's uncle by marriage, educated him in Buddhism and basic skills such as writing and reading. This education is possibly the basis for Yoshikawa Eiji's fictional education of Musashi by the historical Zen monk Takuan. He was apparently trained by Munisai in the sword, and in the family art of the jutte. This training did not last for a very long time, as in 1589, Munisai was ordered by Shinmen Sokan to kill Munisai's student, Honiden Gekinosuke. The Honiden family was displeased, and so Munisai was forced to move four kilometers (~2.5 mi.) away to the village of Kawakami.
In 1592, Munisai died, although Tokitsu believes that the person who died at this time was really Hirata Takehito.
In 1599, three years later, Musashi left his village, apparently at the age of 15 (according to the Tosakushi, "The Registry of the Sakushu Region", although the Tanji Hokin Hikki says he was 16 years old in 1599, which agrees time-wise with the age reported in Musashi's first duel). His family possessions such as furniture, weapons, genealogy, and other records were left with his sister and her husband, Hirao Yoemon.
In 1600, when a war began between the Toyotomi and Tokugawa clans, Musashi apparently fought on the side of the Toyotomi's "Army of the West", as the Shinmen clan (to whom his family owed allegiance) had allied with them. Specifically, he participated in the attempt to take Fushimi castle by assault in July 1600, in the defense of the besieged Gifu Castle in August of the same year, and finally in the Battle of Sekigahara. Some doubt has been cast on this final battle, as the Hyoho senshi denki has Musashi saying he is "no lord's vassal" and refusing to fight with his father (in Lord Ukita's battalion) in the battle. Omitting the Battle of Sekigahara from the list of Musashi's battles would seem to contradict The Book of Five Rings's statement that Musashi fought in six battles, however. Regardless, as the Toyotomi side lost, it has been suggested that Musashi fled as well and spent some time training on Mount Hiko.
Musashi challenged Yoshioka Seijūrō, master of the Yoshioka School, to a duel. Seijūrō accepted, and they agreed to a duel outside Rendaiji in Rakuhoku, in the northern part of Kyoto on 8 March 1604. Musashi arrived late, greatly irritating Seijūrō. They faced off, and Musashi struck a single blow, per their agreement. This blow struck Seijūrō on the left shoulder, knocking him out, and crippling his left arm. He apparently passed on the headship of the school to his equally accomplished brother, Yoshioka Denshichirō, who promptly challenged Musashi for revenge. The duel took place in Kyoto outside a temple, Sanjūsangen-dō. Denshichirō wielded a staff reinforced with steel rings (or possibly with a ball-and-chain attached), while Musashi arrived late a second time. Musashi disarmed Denshichirō and defeated him. This second victory outraged the Yoshioka family, whose head was now the 12-year-old Yoshioka Matashichiro. They assembled a force of archers, musketeers and swordsmen, and challenged Musashi to a duel outside Kyoto, near Ichijō-ji Temple. Musashi broke his previous habit of arriving late, and came to the temple hours early. Hidden, Musashi assaulted the force, killing Matashichiro, and escaping while being attacked by dozens of his victim's supporters. To escape and fight off his opponents he was forced to draw his second sword and defend himself with a sword in each hand. This was the beginning of his niten'ichi sword style. With the death of Matashichiro, this branch of the Yoshioka School was destroyed.
From 1605 to 1612, he travelled extensively all over Japan in musha shugyō, a warrior pilgrimage during which he honed his skills with duels. He was said to have used bokken or bokuto in actual duels. Most of the engagements from these times did not try to take the opponent's life unless both agreed, but in most duels, it is known that Musashi did not care which weapon his foe used — such was his mastery.
A document dated 5 September 1607, purporting to be a transmission by Miyamoto Munisai of his teachings, suggests Munisai lived at least to this date. In this year, Musashi departed Nara for Edo, during which he fought (and killed) a kusarigama practitioner named Shishido Baiken. In Edo, Musashi defeated Musō Gonnosuke, who would found an influential staff-wielding school known as Shintō Musō-ryū. Records of this first duel can be found in both the Shinto Muso-ryu tradition and the Hyōhō Niten Ichi-ryū (Miyamoto Musashi's school). The Shinto Muso Ryu tradition states that, after being defeated by Musashi, Muso Gonnosuke spent time developing a stick-fighting technique to counter swords and beat Musashi in a rematch. There are no current reliable sources outside the Shinto Muso Ryu tradition to confirm that this second duel took place.
Musashi is said to have fought over 60 duels and was never defeated, although this is a conservative estimate, most likely not accounting for deaths by his hand in major battles. In 1611, Musashi began practicing zazen at the Myōshin-ji temple, where he met Nagaoka Sado, vassal to Hosokawa Tadaoki; Tadaoki was a powerful lord who had received the Kumamoto Domain in west-central Kyūshū after the Battle of Sekigahara. Munisai had moved to northern Kyūshū and became Tadaoki's Teacher, leading to the possibility that Munisai introduced the two. Nagaoka proposed a duel with a certain adept named Sasaki Kojirō. Tokitsu believes that the duel was politically motivated, a matter of consolidating Tadaoki's control over his fief.
On April 13, 1612, Musashi (about age 30) fought his duel with Sasaki Kojirō, who was known as "The Demon of the Western Provinces" and who wielded a nodachi, the Japanese great sword. Musashi came late and unkempt to the appointed place — the island of Funajima, in the Kanmon Straits separating Honshū and Kyūshū. The duel was short. Musashi killed his opponent with a bokken that legend says he had carved from an oar used on the boat that carried him to the island.
In 1614–1615, Musashi participated in the war between the Toyotomi and the Tokugawa. The war had broken out because Tokugawa Ieyasu saw the Toyotomi family as a threat to his rule of Japan; most scholars believe that, as in the previous war, Musashi fought on the Toyotomi side. Osaka Castle was the central place of battle. The first battle (the Winter Battle of Osaka; Musashi's fourth battle) ended in a truce. The second (the Summer Battle of Osaka; Musashi's fifth battle) resulted in the total defeat of Toyotomi Hideyori's Army of the West by Ieyasu's Army of the East in May 1615. Some reports go so far as to say that Musashi entered a duel with Ieyasu, but was recruited after Ieyasu sensed his defeat was at hand. This may seem unlikely since Ieyasu was in his 70s and was in poor health already, but it remains unknown how Musashi came into Ieyasu's good graces.
In 1615 he entered the Service of Ogasawara Tadanao (小笠原忠直) of Harima Province, at Ogasawara's invitation, as a "Construction Supervisor," after previously gaining skills in craft. He helped construct Akashi Castle and in 1621 to lay out the organization of the town of Himeji. He also taught martial arts during his stay, specializing in instruction in the art of shuriken(ninja-star)-throwing. During this period of Service, he adopted a son.
In 1621, Musashi defeated Miyake Gunbei and three other adepts of the Togun-ryu in front of the lord of Himeji; it was after this victory that he helped plan Himeji. Around this time, Musashi developed a number of disciples for his Enmei-ryū although he had developed the school considerably earlier; at the age of 22, Musashi had already written a scroll of Enmei-ryū teachings called "Writings on the Sword Technique of the Enmei-ryū" (Enmei-ryū kenpō sho). 円/"En" meant "circle" or "perfection"; 明/"mei" meant "light"/"clarity", and 流/"ryū" meant "school"; the name seems to have been derived from the idea of holding the two swords up in the light so as to form a circle. The school's central idea is given as training to use the twin swords of the samurai as effectively as a combination of sword and jutte.
In 1622, Musashi's adoptive son, Miyamoto Mikinosuke, became a vassal to the Himeji Domain. Possibly this prompted Musashi to leave, embarking on a new series of travels, winding up in Edo in 1623, where he became friends with the Confucian scholar Hayashi Razan, who was one of the Shogun's advisors. Musashi applied to become a swordmaster to the shōgun, but as he already had two swordmasters (Ono Jiroemon Tadaaki and Yagyū Munenori — the latter also a political advisor, in addition to his position as the head of the Shogunate's secret police) Musashi's application was denied. He left Edo in the direction of Ōshū, ending up in Yamagata, where he adopted a second son, Miyamoto Iori. The two then traveled, eventually stopping in Osaka.
In 1626, Miyamoto Mikinosuke, following the custom of junshi, performed seppuku because of the death of his lord. In this year, Miyamoto Iori entered Lord Ogasawara's Service. Musashi's attempt to become a vassal to the lord of Owari, like other such attempts, failed.
In 1627, Musashi began to travel again. In 1634 he settled in Kokura with Iori, and later entered the Service of the daimyō Ogasawara Tadazane, taking a major role in the Shimabara Rebellion. Iori served with distinction in putting down the rebellion and gradually rose to the rank of karō – a position equal to a minister. Musashi, however was reputedly injured by a thrown rock while scouting in the front line, and was thus unnoticed.
Six years later, in 1633, Musashi began staying with Hosokawa Tadatoshi, daimyō of Kumamoto Castle, who had moved to the Kumamoto fief and Kokura, to train and paint. Ironically, it was at this time that the Hosokawa lords were also the patrons of Musashi's chief rival, Sasaki Kojirō. While there he engaged in very few duels; one would occur in 1634 at the arrangement of Lord Ogasawara, in which Musashi defeated a lance specialist by the name of Takada Matabei. Musashi would officially become the retainer of the Hosokowa lords of Kumamoto in 1640. The Niten Ki records "[he] received from Lord Tadatoshi: 17 retainers, a stipend of 300 koku, the rank of ōkumigashira 大組頭, and Chiba Castle in Kumamoto as his residence."
In the second month of 1641, Musashi wrote a work called the Hyoho Sanju Go ("Thirty-five Instructions on Strategy") for Hosokawa Tadatoshi; this work overlapped and formed the basis for the later The Book of Five Rings. This was the year that his third son, Hirao Yoemon, became Master of Arms for the Owari fief. In 1642, Musashi suffered attacks of neuralgia, foreshadowing his Future ill-health. In 1643 he retired to a cave named Reigandō as a hermit to write The Book of Five Rings. He finished it in the second month of 1645. On the twelfth of the fifth month, sensing his impending death, Musashi bequeathed his worldly possessions, after giving his manuscript copy of The Book of Five Rings to the younger brother of Terao Magonojo, his closest disciple. He died in Reigandō cave around June 13, 1645 (Shōhō 3, 30th day of the 4th month). The Hyoho senshi denki described his passing:
Even in Musashi's time there were fictional texts resembling comic books. It is therefore quite difficult to separate fact from fiction when discussing his life. There have been numerous works of fiction made about or featuring Musashi. Eiji Yoshikawa's novelization (originally a 1930s daily newspaper serial) has greatly influenced successive fictional depictions (including the manga Vagabond by Takehiko Inoue) and is often mistaken for a factual account of Musashi's life. In 2012, Writer Sean Michael Wilson and Japanese Artist Chie Kutsuwada published an attempt at a more historically accurate manga entitled The Book of Five Rings: A Graphic Novel, based on research and translations by william Scott Wilson.
As a form, strategy was said to be one of "Ten Abilities and Seven Arts" that a warrior should have, but Musashi disagrees that one person can gain strategy by being confined to one particular style, which seems particularly fitting as he admits "I practice many arts and abilities — all things with no teacher" — this perhaps being one of the reasons he was so highly regarded a swordsman.