In ancient Japan, Shintoism and Buddhism combined into a uniquely Japanese form of religion. During the Fujiwara regency, the military class rose around the ideals of the samurai, and large military families formed around powerful political figures. The Japanese medieval era also saw a shift toward a feudalistic society. Japan managed to repel two Mongol invasions, and a civil war led the country to a period of Ashikaga rule.
Ashikaga rule, known as Muromachi, lasted from 1336 to 1573, and it succeeded the period of the Kamakura rule. The Ashikaga were not as powerful as the Kamakura, and due to the chaos of the civil war, leaders were unable to introduce law and order until the third shogun Ashikaga Yoshimitsu took over. Yoshimitsu allowed strong regional rulers to establish themselves; these leaders would later be called the daimyo, and they eventually served as the shogun's deputies.
Yoshimitsu managed to unite the Northern and Southern Courts. However, the shoguns who followed in Yoshimitsu's footsteps were unable to maintain control or dictate the line of succession, and power increasingly shifted in favor of the daimyo. The Ashikaga family was unable to maintain its own power base and establish a line of succession, resulting in the Onin war, which began in 1467 and was the start of a century of war and chaos.