Dōgen Zenji (道元禅師; 19 January 1200 – 22 September 1253), also known as Dōgen Kigen (道元希玄), Eihei Dōgen (永平道元), Koso Joyo Daishi (高祖承陽大師), or Bussho Dento Kokushi (仏性伝東国師), 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 meditation practice of zazen through literary works such as Fukan zazengi and Bendōwa. 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 Sōtō school today.
Dōgen is known for his extensive writing including his most famous work, the collection of 95 essays called the Shōbōgenzō, but also Eihei Kōroku, a collection of his talks, poetry, and commentaries, and Eihei Shingi, the first Zen monastic code written in Japan, among others.