Yoritomo Minamoto was a prominent Japanese military leader and the founder of the Kamakura shogunate, which marked the beginning of the feudal era in Japan. Born in 1147, he played a crucial role in the Genpei War, a conflict between the Minamoto and Taira clans. After his victory in 1185, he established himself as the first shōgun, or military ruler, of Japan. Yoritomo's leadership transformed the political landscape of Japan, shifting power from the imperial court to military leaders. His governance emphasized the importance of samurai loyalty and established a new system of land management, which laid the groundwork for future shogunates.