History of Japan men instead joined forces with Emperor Go-Daigo and overthrew the Kamakura shogunate. Japan nevertheless entered a period of prosperity and population growth starting around 1250. In rural areas, the greater use of iron tools and fertilizer, improved irrigation techniques, and double-cropping increased productivity and rural villages grew. Fewer famines and epidemics allowed cities to grow and commerce to boom. Buddhism, which had been largely a religion of the elites, was brought to the masses by prominent monks, such as Hōnen (1133–1212), who established Pure Land Buddhism in Japan, and Nichiren (1222–82), who founded Nichiren Buddhism. Zen Buddhism spread widely among
Buddhism in Japan priests, and 569 Buddhist nuns in Japan. The initial period saw the six great Chinese schools, called in Japanese were introduced to the Japanese archipelago: These schools were centered around the ancient capitals of Asuka and Nara, where great temples such as the Asuka-dera and Tōdai-ji were erected respectively. These were not exclusive schools, and temples were apt to have scholars versed in several of the schools. It has been suggested that they can best be thought of as "study groups". The Buddhism of these periods, known as the Asuka period and Nara period – was not a practical religion,