Bakumatsu was the final years of the Edo period when the Tokugawa shogunate ended. Between 1853 and 1867, under foreign diplomatic and military pressure, Japan ended its isolationist foreign policy known as sakoku and changed from a feudal Tokugawa shogunate to the modern empire of the Meiji government. The major ideological-political divide during this period was between the pro-imperial nationalists called ishin shishi and the shogunate forces, which included the elite shinsengumi swordsmen.

Shogun, officially sei-i taishōgun , was the title of the military rulers of Japan during most of the period spanning from 1185 to 1868. Nominally appointed by the Emperor, shoguns were usually the de facto rulers of the country. Although during part of the Kamakura period and Sengoku period, shoguns were figureheads themselves, with real power in the hands of the shikken (執権) of the Hōjō clan and kanrei (管領) of the Hosokawa clan. In addition, Taira no Kiyomori and Toyotomi Hideyoshi were leaders of the warrior class who did not hold the position of shogun, the highest office of the warrior class, yet gained the positions of daijō-daijin and kampaku , the highest offices of the aristocratic class. As such, they ran their governments as its de facto rulers.