Zhaozhou became ordained as a monk at an early age. At the age of 18, he met Nánquán Pǔyuàn (南泉普願 748–835; J: Nansen Fugan), a successor of Mǎzǔ Dàoyī (709–788; J. Baso Do-itsu), and eventually received the Dharma from him. When Nanquan asked Zhaozhou the koan "What is the Way?", the two had a dialogue, at the height of which Zhaozhou attained enlightenment. Zhaozhou continued to practice under Nanquan until the latter's death.
Subsequently, Zhaozhou began to travel throughout China, visiting the prominent Chan masters of the time before finally, at the age of eighty, settling in Guānyīnyuàn (觀音院), a ruined temple in northern China. There, for the next 40 years, he taught a small group of monks.
Zhaozhou is sometimes touted as the greatest Chan master of Tang dynasty China during a time when its hegemony was disintegrating as more and more regional military governors (jiédùshǐ) began to assert their power. Zhaozhou's lineage died out quickly due to the many wars and frequent purges of Buddhism in China at the time, and cannot be documented beyond the year 1000.
Many koans in both the Blue Cliff Record and The Gateless Gate concern Zhaozhou, with twelve cases in the former and five in the latter being attributed to him. He is, however, probably best known for the first koan in The Gateless Gate:
A monk asked Chao-chou, "Has the dog Buddha-nature or not?" Chao-chou said, "Wu." (Source Accessed July, 15, 2021)
