The Boshin War (???? Boshin Senso) was a civil war in Japan; fought from 1868 to 1869 between forces of the ruling Tokugawa Shogunate and those seeking to return political power to the imperial court.

The war found its origins in dissatisfaction among many nobles and young samurai with the shogunate's handling of foreigners following the opening of Japan during the prior decade. An alliance of western samurai (particularly the domains of Choshu; Satsuma and Tosa) and court officials secured control of the imperial court and influenced the young Emperor Meiji. Tokugawa Yoshinobu; the sitting shogun; realizing the futility of his situation; abdicated political power to the emperor. Yoshinobu had hoped that by doing this; the Tokugawa house 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 Choshu abolishing the house of Tokugawa led Yoshinobu to launch a military campaign to seize the emperor's court at Kyoto. The military tide rapidly turned in favor 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 retreated to northern Honshu and later to Hokkaido; where they founded the Ezo republic. Defeat at the Battle of Hakodate broke this last holdout and left the imperial rule supreme throughout the whole of Japan; completing the military phase of the Meiji Restoration.