Dōgen Zenji (道元禅師; 19 January 1200 – 22 September 1253), was a Japanese Buddhist priest, writer, poet, philosopher, and founder of the Sōtō school of Zen in Japan.

Originally ordained as a monk in the Tendai School in Kyoto, he was ultimately dissatisfied with its teaching and traveled to China to seek out what he believed to be a more authentic Buddhism. He remained there for five years, finally training under Tiantong Rujing, an eminent teacher of the Chinese Caodong lineage. Upon his return to Japan, he began promoting the practice of zazen (sitting meditation) through literary works such as Fukan zazengi and Bendōwa.

Cited from https://en.wikipedia.org/wiki/D%C5%8Dgen