Kuo-ch’ing-ssu ［国清寺］ (PY Guoqingsi;  Kokusei-ji): A temple of the T’ien-t’ai school on Mount T’ien-t’ai in China. It was built in 598, the year after T’ien-t’ai’s death (601 according to another account), by Prince Kuang of the Sui dynasty (later known as Emperor Yang of that dynasty) in compliance with T’ien-t’ai’s will. Chang-an, T’ien-t’ai’s successor, lived at Kuo-ch’ing-ssu, which prospered as the school’s main center of practice. When Dengyō, who later founded the Japanese Tendai school, and his disciple Gishin went to China in 804, they studied at this temple. Many other Japanese priests studied there as well, among them Enchin (the fifth chief priest of the Tendai school head temple Enryaku-ji) and Eisai (the founder of the Rinzai school of Zen in Japan).