The school of Zen called Soto in Japan was founded in China by Ch'an masters Tung-shan Liang-chieh (807-869; Tozan Ryokai in Japanese) and Ts'ao-shan Pen-chi (840-901; Sozan Honjaku in Japanese). The school was named Ts'ao-Tung (Soto in Japanese) after the names of its founders.
Soto Zen was brought to Japan by Eihei Dogen (1200-1253), also called Dogen Kigen or Dogen Zenji. Dogen, a Tendai monk, went to China in 1223 to study with Ts'ao-Tung master T'ien-t'ung Ju-shing. Under this teacher, Dogen realized enlightenment and became the first Japanese lineage holder of Ts'ao-Tung.
Dogen returned to Japan in 1227 to establish Soto Zen in Japan, where it has flourished to this day. Dogen's influence is still felt in Soto Zen, and his body of writing, in particular Shobogenzo, is considered one of the great works of Japanese religious literature.