慧开 was his dharma name and
无门, 'no gate', his title. He is said to have worked for six years on the koan of Zhaozhou's dog, answered with the single word
无, before his awakening. In 1228 he gathered 48 koans with his comments and verses as 《
无门关》, which a Japanese disciple carried to Japan, where Zen monks still train with it as the Mumonkan.
