ennin

Ennin (円仁), also romanized as Ennin, was a Japanese Buddhist monk of the Tendai school who lived in the 9th century (approximately 794–864). He is best known for undertaking a long journey to Tang China to study Buddhism and for bringing back texts and teachings that influenced the development of Japanese Tendai practice.

Born in the late Nara or early Heian period, Ennin joined the Tendai line of Buddhist transmission, which would later be associated with institutions such as Enryaku-ji on Mount Hiei. Around 838, he departed Japan for China and studied at Tang Buddhist centers, engaging with authorities and monastic communities there. During his stay, he is said to have collected sutras, ritual manuals, and other scholarly materials, which he transmitted to his homeland upon his return.

Ennin’s account of his travels is preserved in his travel diary, a valuable primary source for historians. The diary provides insights into Tang-era Buddhist practice, Sino-Japanese religious exchange, and contemporary political and cultural life. Although the diary contains some embellishments and its details are debated by scholars, it remains a key document for understanding early Japanese reception of Chinese Buddhism.

On his return to Japan, Ennin contributed to the transmission and interpretation of Tang Chinese Buddhist texts within the Tendai tradition and influenced the intellectual and liturgical development of Japanese Buddhist practice. His legacy lies in helping to connect Japanese monastic scholarship with Chinese Buddhist thought during a formative period of Japanese Buddhism.

See also: Tendai school, Tiantai, Enryaku-ji, Tang dynasty.