Dogen Zenji (????; 19 January 1200 – 22 September 1253), also known as Dogen Kigen (????), Eihei Dogen (????), Koso Joyo Daishi (??????), or Bussho Dento Kokushi (??????), was a Japanese Buddhist priest, writer, poet, philosopher, and founder of the Soto 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 Bendowa.
He eventually broke relations completely with the powerful Tendai School, and, after several years of likely friction between himself and the establishment, left Kyoto for the mountainous countryside where he founded the monastery Eihei-ji, which remains the head temple of the Soto school today.
Dogen is known for his extensive writing including his most famous work, the collection of 95 essays called the Shobogenzo, but also Eihei Koroku, a collection of his talks, poetry, and commentaries, and Eihei Shingi, the first Zen monastic code written in Japan, among others.