Battle of Miyako Bay

The Battle of Miyako Bay (宮古湾海戦) was a naval action on 6 May 1869. It was part of the overall Battle of Hakodate at the end of the Boshin War, a civil war in Japan between Imperial forces of the new government, and samurai rebels that wanted to maintain the feudal caste system.

Preparations
After the remnants of the Bakufu army loyal to the former Tokugawa shogunate refused to surrender to the new Meiji government in the Battle of Ueno and Battle of Aizu, they fled north to occupy the island of Hokkaidō and established the Republic of Ezo. The navy of the Imperial forces also moved north to support the eventual invasion of Hokkaidō.

The Imperial navy departed Tokyo on 9 March 1869, and reached the harbor of Miyako, north of Sendai, on 20 March. The government fleet had been rapidly constituted around the French-built ironclad warship Kōtetsu, which had been purchased from the United States. Other ships included Kasuga, Hiryū, Teibo, Yoshun, and Moshun, which had been supplied by the domains of Saga, Chōshū and Satsuma to the new central government in 1868. There were altogether eight Imperial ships: Kōtetsu, Kasuga, 3 small corvettes and 3 transport ships.

Anticipating the arrival of the Imperial fleet, the rebels organized a plan to seize the revolutionary new warship Kōtetsu, and dispatched three warships for a surprise attack:
 * Kaiten (flagship of the Republic of Ezo Navy). Kaiten was commanded by Arai Ikunosuke, and contained the elite Shinsengumi, their leader Hijikata Toshizo, as well as the former French Navy military advisor Henri Nicol. Nicol had been selected for the attack since he was a native of Bordeaux, and knew the characteristics and construction of the revolutionary warship Kōtetsu, built in the same city.
 * Banryu, with the elite Yugekitai (遊撃隊) and former French Navy quartermaster Clateau, in charge of cannonry.
 * Takao (former USRC Ashuelot) under command of ex-French Navy officer Eugène Collache, with the elite Shinkitai (伸木隊)].

The ships encountered bad weather, in which Takao suffered from engine trouble, and Banryu became separated. Banryu eventually returned to Hokkaidō, without joining the battle.

Action
To create surprise, Kaiten planned to enter Miyako harbor under an American flag. Unable to achieve more than 3 kn due to engine trouble, Takao trailed behind, and Kaiten first joined battle.

Kaiten approached the enemy ships and raised the Republic of Ezo flag seconds before boarding Kōtetsu. She rammed her prow into the side of Kōtetsu, and started firing her guns. Her deck however proved higher than that of Kōtetsu by close to three meters, forcing the samurai to jump one by one in a trickle. After the first surprise passed, Kōtetsu managed to repel the attack with a Gatling gun, causing huge losses to the attackers. Most of the attacking samurai perished; Nicol was hit by two bullets, and boarding party commander Koga Gengo was killed and his position taken over by Admiral Arai Ikunosuke. In the action, Kaiten damaged three enemy warships, but finally disengaged without having captured Kōtetsu.

Kaiten steamed out of Miyako Bay pursued by the Imperial fleet (which had been warming up their engines even before the attack began), just as Takao was entering. Kaiten eventually escaped to Hokkaidō, but Takao was too slow to outdistance its pursuers and was beached at little distance from Miyako Bay, so that her crew could escape inland, and was scuttled by explosion. The 40 crewmen (including 30 samurai and the ex-French officer Eugène Collache) managed to flee for a few days, but finally surrendered to government forces. They were brought to Tokyo for imprisonment and trial. Although the fate of the Japanese rebels is unknown, Collache was eventually pardoned and deported back to France.

Conclusion
The Naval Battle of Miyako was a daring but desperate attempt by the Republic of Ezo forces to neutralize the powerful Kōtetsu. It was the first case of an abordage (boarding) maneuver in Japan. Although the attempt ended in failure, the loss of the Takao was marginal. The Imperial Navy continued north unimpeded, and supported landing and combat operations of thousands of government troops in the Battle of Hakodate.