The Boshin War (戊辰戦争, Boshin Sensō), sometimes known as the Japanese Revolution or Japanese Civil War, was a civil war in Japan fought from 1868 to 1869 between forces of the ruling Tokugawa shogunate and a coalition seeking to seize political power in the name of the Imperial Court.
The war stemmed from dissatisfaction among many nobles and young samurai with the shogunate's handling of foreigners following the opening of Japan during the prior decade. Increasing Western influence in the economy led to a decline similar to that of other Asian countries at the time. An alliance of western samurai, particularly the domains of Chōshū, Satsuma, and Tosa, and court officials secured control of the Imperial Court and influenced the young Emperor Meiji. Tokugawa Yoshinobu, the sitting shōgun, realizing the futility of his situation, abdicated and handed over political power to the emperor. Yoshinobu had hoped that by doing this the House of Tokugawa could be preserved and participate in the future government.
However, military movements by imperial forces, partisan violence in Edo, and an imperial decree promoted by Satsuma and Chōshū abolishing the House of Tokugawa led Yoshinobu to launch a military campaign to seize the emperor's court in Kyoto. The military tide rapidly turned in favour of the smaller but relatively modernized Imperial faction, and, after a series of battles culminating in the surrender of Edo, Yoshinobu personally surrendered. Those loyal to the Tokugawa shōgun retreated to northern Honshū and later to Hokkaido, where they founded the Republic of Ezo. The defeat at the Battle of Hakodate broke this last holdout and left the Emperor as the de facto supreme ruler throughout the whole of Japan, completing the military phase of the Meiji Restoration.
Around 69,000 men were mobilized during the conflict, and of these about 8,200 were killed. In the end, the victorious Imperial faction abandoned its objective of expelling foreigners from Japan and instead adopted a policy of continued modernization with an eye to the eventual renegotiation of the unequal treaties with the Western powers. Due to the persistence of Saigō Takamori, a prominent leader of the Imperial faction, the Tokugawa loyalists were shown clemency, and many former shogunate leaders and samurai were later given positions of responsibility under the new government.
When the Boshin War began, Japan was already modernizing, following the same course of advancement as that of the industrialized Western nations. Since Western nations, especially the United Kingdom and France, were deeply involved in the country's politics, the installation of Imperial power added more turbulence to the conflict. Over time, the war was romanticized as a "bloodless revolution", as the number of casualties was small relative to the size of Japan's population. However, conflicts soon emerged between the western samurai and the modernists in the Imperial faction, which led to the bloodier Satsuma Rebellion nine years later.
Boshin (戊辰) is the designation for the fifth year of a sexagenary cycle in traditional East Asian calendars. Although the war lasted for over a year, Boshin refers to the year in which the war started. The characters 戊辰 can also be read as tsuchinoe-tatsu in Japanese, literally "Elder Brother of Earth-Dragon". In Chinese, it translates as "Yang Earth Dragon", which is associated with that particular year in the sexagenary cycle. The war started in the fourth year of the Keiō era, which also became the first year of the Meiji era in October of that year, and ended in the second year of the Meiji era.
Early discontent against the shogunate
For the two centuries prior to 1854, Japan had a strict policy of isolationism, restricting all interactions with foreign powers, with the notable exceptions of Joseon Korea via Tsushima, Qing China via the Ryukyu Islands, and the Dutch through the trading post of Dejima. In 1854, the Perry Expedition, led by Matthew C. Perry of the United States Navy (USN), opened Japan to global commerce, initiating rapid development of foreign trade and Westernization. In large part due to the humiliating terms of the unequal treaties, as agreements like those negotiated by Perry are called, the Tokugawa shogunate soon faced internal dissent, which coalesced into a radical movement, the sonnō jōi (meaning "revere the Emperor, expel the barbarians").
Emperor Kōmei agreed with such sentiments and, breaking with centuries of Imperial tradition, began to take an active role in matters of state: as opportunities arose, he vehemently protested against the treaties and attempted to interfere in the shogunal succession. His efforts culminated in March 1863 with his "order to expel barbarians". Although the shogunate had no intention of enforcing it, the order nevertheless inspired attacks against the shogunate itself and against foreigners in Japan: the most famous incident was that of the English trader Charles Lennox Richardson, for whose death the Tokugawa government had to pay an indemnity of one hundred thousand British pounds. Other attacks included the shelling of foreign shipping in the port of Shimonoseki.
In 1863 and 1864, these actions were successfully countered by armed retaliations by foreign powers, such as the British bombardment of Kagoshima and the multinational Shimonoseki campaign. On 20 August 1864, the forces of Chōshū Domain, together with rōnin, raised the Hamaguri rebellion trying to seize the city of Kyoto, where the Emperor's court was, but were repelled by shogunate forces under the future shōgun Tokugawa Yoshinobu. The shogunate further ordered a punitive expedition against Chōshū, the First Chōshū expedition, and obtained Chōshū's submission without actual fighting. At this point the initial resistance among the leadership in Chōshū and the Imperial Court subsided, but over the next year the Tokugawa proved unable to reassert full control over the country as most daimyōs began to ignore orders and questions from the Tokugawa seat of power in Edo.
The Shogun had sought French assistance for training and weaponry since 1865. Léon Roches, French consul to Japan, supported the Shogunal military reform efforts to promote French influence, hoping to make Japan into a dependent client state. This caused the British to send their own military mission to compete with the French.
Despite the bombardment of Kagoshima, the Satsuma Domain had become closer to the British and was pursuing the modernization of its army and navy with their support. The Scottish merchant Thomas Blake Glover sold quantities of warships and guns to the southern domains. American and British military experts, usually former officers, may have been directly involved in this military effort. The British ambassador, Harry Smith Parkes, supported the anti-shogunate forces in a drive to establish a legitimate, unified Imperial rule in Japan, and to counter French influence with the shogunate. During that period, southern Japanese leaders such as Saigō Takamori of Satsuma, or Itō Hirobumi and Inoue Kaoru of Chōshū cultivated personal connections with British diplomats, notably Ernest Mason Satow. Satsuma domain received British assistance for their naval modernisation, and they became the second largest purchaser of western ships after the Shogunate itself, of which nearly all were British-built. As Satsuma samurai became dominant in the Imperial navy after the war, the navy frequently sought assistance from the British.
In preparation for future conflict, the shogunate also modernized its forces. In line with Parkes's strategy, the British, previously the shogunate's primary foreign partner, proved reluctant to provide assistance. The Tokugawa thus came to rely mainly on French expertise, comforted by the military prestige of Napoleon III at that time, acquired through his successes in the Crimean War and the Second Italian War of Independence.
The shogunate took major steps towards the construction of a modern and powerful military: a navy with a core of eight steam warships had been built over several years and was already the strongest in Asia. In 1865, Japan's first modern naval arsenal was built in Yokosuka by the French engineer Léonce Verny. In January 1867, a French military mission arrived to reorganize the shogunate army and create the Denshūtai elite force, and an order was placed with the US to buy the French-built ironclad warship CSS Stonewall, which had been built for the Confederate States Navy during the American Civil War. Due to the Western powers' declared neutrality, the US refused to release the ship, but once neutrality was lifted, the imperial faction obtained the vessel and employed it in engagements in Hakodate under the name Kōtetsu ("Ironclad").