Knights would protect districts from invaders under the king's command. There was feudalism in medieval Europe from the 4th to the 12th century and in Medieval Japan from 1185 to 1603. Feudalism was a social system of rights and obligations based on land ownership. Japan and European feudalism were similar in many significant ways.

In medieval Europe and Japan, there was a social pyramid. In Europe's social pyramid were peasants, merchants, knights, lords, and kings. Kings were at the top, and peasants or merchants were at the bottom. Japan also had feudalism, so they also had a social pyramid. Their social pyramid comprises merchants, peasants, Saimiri, shogun, daimyo, and emperors. Emperors were at the top, and peasants and merchants were