Feudalism, also known as the feudal system, was a combination of legal, economic, military, cultural, and political customs that flourished in medieval Europe from the 9th to 15th centuries. Broadly defined, it was a way of structuring society around relationships derived from the holding of land in exchange for service or labour.

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.