This final duel was between Musashi and an equally renowned swordsman of the Edo era, Sasaki Kojiro 佐々木 小次郎, on Funashima Island, Funa-jima 船島.
April 13th, 1612, was also the day of Sasaki’s death. Born in 1585 in Fukui Prefecture, Sasaki Kojiro was twenty-seven years old when he died, two years younger than Musashi had been at the time of their duel.
At the time of this battle in 1612, Musashi had just begun practicing zazen meditation for a year and was thought to have been without a definite place of residence as he traveled the country.
It was not until twenty-two years later in 1634 that Musashi would return to live in the nearby area of Kokura at Kokura Castle as a guest of the daimyo Lord Ogasawara Tadazane.
Located in the Kannon Straits between Kita-Kyushu and Yamaguchi, Japan, Funa-jima 船島 remains a place of importance in the history of martial arts and samurai battle.
Following this historical duel between Musashi and Sasaki, Funashima island was renamed Ganryu-jima 巌流島 after Kojiro Sasaki and his school.
Ganryu-jima is uninhabited today and is accessible only during daytime by ferry from two points, Shimonoseki Port, Yamaguchi and from Mojiko, Kita-Kyushu.
When the sun sets, Ganryu-jima also sets and is not reachable until the following sunrise.
The fact that this final battle for both Musashi and Sasaki had been on an island is an important detail.
Since the island is completely surrounded by ocean, Musashi could only arrive to the duel by boat.
As Musashi was being ferried to Ganryu-jima in a wooden boat, legend recounts that Musashi carved a sword out of an oar. It was with this wooden sword that Miyamoto Musashi defeated Sasaki Kojiro.
Folklore also recites that Musashi calculated the hour of his arrival as well as his departure from Ganryu-jima to coincide with the turning of the ocean tides to facilitate his entry and exit from the battle, hence, maximising his potential for victory.
Not only was Miyamoto Musashi aware of the moon and its pull on the ocean as it exerted on the ebb and flow of the tides, he also calculated the position of the sun in the sky that day to possibly blind Sasaki Kojiro with the sun rays as they fought.
While these stories cannot be verified as facts today, the myths underline the lessons that Musashi imparts in his writings about the necessity to not only understand ourselves and our opponent while possessing the skill to draw upon our own practice to win in conflict, but that a warrior must also grasp his/ her external environment and utilise the forces of nature as strategic resources to achieve success in battle, as in life.
By the age of thirty, Musashi had come to discover that he had remained undefeated throughout his life as a warrior on the battlefield and in sword-wielding combats by having realised the essence of nature in his approach to sword fighting.
Musashi would spend the following thirty years of his life sharpening his understanding the nature of conflict and refining his practice in the art of the sword-wielding.
The purity of his heart, the clarity of his mind, the flexibility of his hands as he wielded swords along with paintbrushes, coupled with his devotion to arrive at Truth until his death transformed Musashi from a ronin, a warrior into a Sword-Saint.