and the lowest class was that of the cheonmin. Between the yangban and the commoners was a fourth class, the chungin, "middle people". Joseon Korea installed a centralised administrative system controlled by civil bureaucrats and military officers who were collectively called Yangban. Yangban strove to do well at the royal examinations to obtain high positions in the government. They had to excel in calligraphy, poetry, classical Chinese texts, and Confucian rites. In order to become an official, one had to pass a series of gwageo examinations. There were three kinds of gwageo exams – literary, military, and miscellaneous. Edo Japan In 1603, the Tokugawa shogunate (military dictatorship) ushered in a long period of isolation from foreign influence in order to secure its power. For 250 years this policy enabled Japan to enjoy stability and a flowering of its indigenous culture. Early modern Japanese society had an elaborate social structure, in which everyone knew their place and level of prestige. At the top were the emperor and the court nobility, invincible in prestige but weak in power. Next came the "bushi" of shōgun, daimyō and layers of feudal lords whose rank was indicated by their closeness to the Tokugawa. They had power. The "daimyō" were about 250 local lords of local "han" with annual outputs of 50,000 or more bushels of rice. The upper strata was much given to elaborate and expensive rituals, including elegant architecture, landscaped gardens, nō drama, patronage of the arts, and the tea ceremony. Three cultures Three distinct cultural traditions operated during the Tokugawa era, having little to do with each other. In the villages the peasants had their own rituals and localistic traditions. In the high society of the imperial court, daimyō and samurai, Chinese cultural influence was paramount, especially in the areas of ethics and political ideals. Neo-Confucianism became the approved philosophy, and was taught in official schools; Confucian norms regarding personal duty and family honor became deeply implanted in elite thought. Equally pervasive was the Chinese influence in painting, decorative arts and history, economics, and natural science. One exception came in religion, where there was a revival of Shinto, which had originated in Japan. Motoori Norinaga (1730–1801) freed Shinto from centuries of Buddhist accretions and gave a new emphasis to the myth of imperial divine descent, which later became a political tool for imperialist conquest until it was destroyed in 1945. The third cultural