Battle of Aizu

In the fourth year of the Keiō era (1868), the Boshin War—fought over the establishment of the new Meiji government—approached its greatest climax. The Aizu domain, a major power of northeastern Japan, under its lord Matsudaira Katamori—who as Kyoto protector had served to maintain order on the Tokugawa side—chose the path of thorough resistance despite being branded "enemy of the emperor" by the new government forces. Thus the Battle of Aizu, which commenced in August, became inscribed in history as the most tragic engagement of the late Edo and Meiji Restoration periods.

The Background of the War—The Nature of Aizu Domain

Aizu domain was bound by the "Fifteen Precepts of the Aizu House Code," established in the age of Tokugawa Iemitsu, to pledge absolute loyalty to the shogunal house. The severe martial education encapsulated in the motto "That which must not be, must not be" took deep root within the domain, and its samurai absorbed this spirit into the very core of their beings.

Lord Matsudaira Katamori assumed the office of Kyoto protector in the second year of Bunkyū (1862), placing the Shinsengumi under his command to suppress sonnō-jōi activists. His achievements in the Ikedaya Incident (1864) and the Hamaguri Uprising (1864) enhanced the shogunate's trust in him, yet simultaneously incurred the hatred of anti-Tokugawa domains such as Chōshū and Satsuma. When the Tokugawa forces suffered defeat at the Battle of Toba-Fushimi (January 1868), Aizu domain was branded an "enemy of the emperor" and became a target of suppression by the new government forces.

Blades and Armament—Military Transformation in the Late Edo Period and Aizu Kanesada

The Battle of Aizu marked an important turning point in the history of Japanese warfare. The new government forces were already equipped with numerous Western-style rifles—Gébels and Sniders—and artillery, while Aizu domain, though not relying solely on antiquated swords and spears, possessed a certain number of Western-style firearms. Yet in modern military training and organizational capacity, the gap between Aizu and the new government forces was undeniable.

Nevertheless, blades continued to play roles both spiritual and practical in this battle. For the samurai of Aizu domain, the sword worn at the side was not mere weaponry, but a symbol of the soul embodying the precept "That which must not be, must not be." Records survive of hand-to-hand combat—blade-to-blade skirmishes—occurring during phases of the castle siege, in which swords saw actual use.

The swords of the "Aizu Kanesada" lineage, known smiths of this period, were widely employed as practical blades by local warriors. The Aizu Kanesada, descending from Koreshigematsu (Kanesada II), is renowned as the lineage that forged the beloved sword of Hijikata Toshizō, the "Izumi no Kami Kanesada," and represents a quintessential wartime blade of the late Edo period. The deep connection forged between the land of Aizu and the name of the swordsmith Kanesada during this war is noteworthy from the perspective of sword history.

Aizu Kanesada is said to have been worked by multiple smiths in the late Edo period as "Koreshigematsu copies," and among modern sword enthusiasts it remains the leading example of a practical late-Edo blade. These blades pursued not merely cutting ability, but emphasized durability and battlefield utility; their hamon and ji structure demonstrate a swordsmith's intention that the blade be forged for use on the battlefield itself. By bearing such a sword, the samurai of Aizu domain embodied the pride of their domain and the spirit of bushidō.

The Course of Battle—The Tragedy of the White Tiger Unit

On the twenty-third of August, the great army of the new government forces began its offensive into Aizu-Wakamatsu. Against the official troops pressing in from all directions, Aizu domain samurai mounted fierce defensive operations at various points throughout the castle town.

On this day, one event in particular would be passed down to posterity: the tragedy of the "Byakkotai"—the White Tiger Unit. The White Tiger Unit consisted of youths aged sixteen to seventeen, and when twenty members of the Second Company observed the state of the castle town from the slopes of Iimoriyama hill, they saw the city engulfed in smoke and mistakenly concluded that "Tsuruga Castle has fallen." Believing that "should the castle fall, there is no path for a samurai to live," all twenty drew their blades and took their own lives. In fact, Tsuruga Castle had not yet fallen at that moment and would hold out until later. Of the twenty youths, one—Iinuma Sadakichi—miraculously revived; the remaining nineteen perished.

The tragedy of the White Tiger Unit became deeply etched in subsequent generations as a pure manifestation of bushidō. Iimoriyama hill has become a sacred site visited by countless pilgrims, and the graves of the White Tiger Unit draw young people from throughout the nation. Reproductions of the short swords carried by these youths are now preserved in museums within Aizu-Wakamatsu city, bearing witness to the final moments of these young samurai. The short swords used by the White Tiger Unit, though their smiths are unknown, are said to have been manufactured as practical implements within Aizu domain, and their pristine appearance moves all who behold them.

The siege continued for approximately one month. Within the castle, food and ammunition began to run short, and many non-combatants—women and children—took refuge within its walls. Matsudaira Katamori attempted to continue resistance until the end, but on the twenty-second of September (lunar calendar), he ultimately made the decision to surrender.

Female Warriors and Blades in the Besieged Castle—The Valor of the Jōshigun

Of particular note in the Battle of Aizu is the participation of women in combat. Women called the "Jōshigun"—the Maiden Corps—took up the naginata and stood on the battlefield, with some meeting their end there. Among them, Nakano Takeko fought valiantly with the naginata on the same day as the White Tiger Unit, the twenty-third of August, suffered a grievous wound from gunfire, and asked her younger sister to strike her down. She was twenty-one years of age. Her naginata has been passed down as a relic and stands as a symbol of the martial arts and valor of the female warrior.

Likewise, Chiyoko, wife of the chief retainer Saigoō Yoribe, took her own life along with twenty-one other women of the Saigoō household. The blade was the soul of the samurai, yet in this war women also took up swords and naginata, and met their end with the pride befitting those born to samurai houses.

The naginata has long been positioned as a woman's weapon in Japanese tradition, yet history shows it was encouraged for women to master it as martial discipline. In the Edo period warrior households, naginata practice was considered part of a bride's education, and the women of Aizu demonstrated their skill in actual combat—a choice of honor befitting those born to samurai houses, rather than mere sacrifice.

Post-War Settlement and Aizu's Lingering Resentment

Following surrender, Aizu domain was abolished and Matsudaira Katamori placed under confinement. The samurai were forced to relocate to the Tonami domain in the barren Shimokita Peninsula, where they endured harsh circumstances. The war dead were long denied proper burial, and the bitter resentment toward this treatment came to be known as "Aizu's lingering resentment," a wound passed down to the present day.

The remains of Aizu domain samurai were finally granted official burial in the late Meiji period, and are interred at Amidaji and Chōmyōji temples in Aizu-Wakamatsu. Tsuruga Castle was demolished in the seventh year of Meiji (1874), but was reconstructed in the fortieth year of Shōwa (1965) and now stands as a symbol of Aizu-Wakamatsu city, welcoming numerous visitors.

The Memory of the Battle of Aizu and Sword Culture in the Modern Era

In Aizu-Wakamatsu city, multiple facilities and museums display swords related to Aizu domain. The Aizu Museum exhibits relics of the White Tiger Unit alongside swords of the Aizu Kanesada lineage, bearing testimony to the actual appearance of the blades used by late-Edo samurai.

Additionally, each September the "Aizu Festival" is held, during which the White Tiger Unit procession and the daimyo's retinue parade through the castle town. The sight of participants dressed as armed domain samurai in this festival speaks to the continued transmission of Aizu's bushidō spirit in the modern age.

The Battle of Aizu stands as a historical event condensing "samurai loyalty and tragedy" during the tumultuous late Edo period, and is indispensable when discussing Japanese sword and bushidō culture. That memory, each time Tsuruga Castle's keep is suffused with the glow of sunset and tinged orange, evokes the very light that fell upon the eyes of the White Tiger youths at their final moment. The spirits of samurai who lived by the blade and departed with the blade still dwell in the land of Aizu.

The Sword Collections of Aizu Domain and Celebrated Blades

Aizu domain is known for the deep affection successive lords harbored toward swords and blades. In particular, Hoshina Masayuki—founder of the Aizu Matsudaira line and half-brother of Tokugawa Iemitsu—devoted himself to sword collecting and preserved many celebrated blades within the domain. Works attributed to Sengo Masamune, known as "Aizu Masamune," are said to have passed into the possession of Aizu domain, with questions raised as to their whereabouts amid the late Edo upheaval.

Matsudaira Katamori himself possessed deep knowledge of swords and blades. During his tenure as Kyoto protector, he received offerings of celebrated swords from master smiths of various domains. Following the defeat in the Battle of Aizu, domain properties were confiscated, yet certain celebrated blades passed through the hands of samurai and have survived to the present day. This history of the dispersal and preservation of celebrated blades, together with the bushidō spirit of Aizu, has been handed down to modern times, and sword enthusiasts who visit Aizu-Wakamatsu continue unabated.