Numerous official missions of envoys, priests, and students were sent to China in the seventh century. Some remained twenty years or more; many of those who returned became prominent reformers. In a move greatly resented by the Chinese, Shotoku sought equality with the Chinese emperor by sending official correspondence addressed "From the Son of Heaven in the Land of the Rising Sun to the Son of Heaven of the Land of the Setting Sun." Shotoku's bold step set a precedent: Japan never again accepted a subordinate status in its relations with China.