Born to an aristocratic family in Kyoto, Dogen was orphaned as a child and entered the Tendai Buddhist monastery of Enryakuji in 1213. Disillusioned by its worldliness, he left in 1214 and entered a Zen temple.
Between 1223 and 1227 he continued his studies in China, where he achieved enlightenment under the Chinese Zen master T'ien-t'ung Ju-ching, who made him his successor.
After returning to Japan in 1231, Dogen began to write his religious classic Shobo Genzo (Treasury of the True Dharma Eye). In 1233 he moved to Kannon Doriin, a temple in Echizen (modern-day Fukui Prefecture) which became the nucleus of his new Soto sect. Driven out of Kannon Doriin in about 1242 by jealous Tendai monks, he finished Shobo Genzo shortly before his death.
The five main tenets of Dogen's sect were:
"Oneness of Practice and Attainment" (practice of meditation, especially daily zazen [sitting meditation], is tied to enlightenment);
"Zazen" (zazen is not a means to enlightenment but, if practiced correctly, is enlightenment);
"All Beings Are Buddha Nature" (Buddha nature is not a potentiality waiting to be awakened in the devotee, but an actuality realized in zazen);
"Buddha Nature Is Impermanence" (Buddha nature does not reach beyond impermanence but is one with it); and
"Uji" (beings and time are inseparable)