[The origination of surgery (Kinso treatment) in Japan]

From the Nara period through to the end of the Heian and early Kamakura periods, the population of Japan grew by 50% thanks to increases in rice cultivation. Such expanded food production resulted in changes in the social structure providing opportunities to those in control of armed forces to become local feudal lords. Many wars fought in the process necessitated the development of treatment methods for Kinso (wounds caused by swords, spears, and similar weapons), to which Jinsoes (Buddhist monks/doctors that accompanied troops) attended, making extensive use of herbal medicine that had been developed by the people of the time. Many war commanders brought Jinsoes to battle fields, which became a custom during the Sengoku (warring) period. As many of the Jinsoes were well educated, they also served as entertainers to the commanders through their knowledge in Go or Renga (a game involving popular poetical verses). Their talents and training eventually resulted in many of the so called traditional arts including Noh, Kabuki, tea ceremony and earthenware production.