The founder of the Japanese Tendai school 天台 — one of the two founding figures (with Kūkai 空海) of the Heian-era Buddhist establishment that defined Japanese Buddhism for the next millennium. Japanese name Saichō 最澄; posthumous title Dèngyō Daishi 傳教大師 (“Great Master of the Transmission of the Teaching”). Born 767 CE; died 822 CE.
He undertook the foundational Tang study mission of 804–805 (Yánlì 延曆 23–24 in the Japanese Heian calendar; Zhēnyuán 貞元 20 – Yǒngzhēn 永貞 1 of the Tang) — together with the parallel mission of Kūkai in the same fleet — bringing back to Japan the entire Tang-period Tiāntái doctrinal corpus along with substantial Esoteric ritual transmissions.
He studied at:
- Tāizhōu 台州 (in Zhèjiāng, the principal Tiāntái-school center) under Dàosuì 道邃 (744–823?), receiving the foundational Tiāntái doctrinal texts and the bodhisattva precepts.
- Yuèzhōu 越州 at Lóngxīngsì 龍興寺 under Shùnxiǎo 順曉, receiving Esoteric initiation and ritual transmissions.
He documented his importation in two catalogs:
- Chuánjiào dàshī jiānglái Tāizhōu lù 傳教大師將來台州錄 (KR6s0105, T2159) — the Tāizhōu portion.
- Chuánjiào dàshī jiānglái Yuèzhōu lù 傳教大師將來越州錄 (KR6s0106, T2160) — the Yuèzhōu portion.
On returning to Japan in 805, he established the Hieizan Enryaku-ji 比叡山 延曆寺 monastic complex on Mount Hiei outside Heian-kyō (Kyoto) as the founding center of Japanese Tendai. The Tendai school’s distinctive Tiāntái-Esoteric integration (called Taimitsu 台密) — combining the doctrinal-meditative Tiāntái system with ritual-Esoteric vajrayāna — became one of the defining features of Japanese Buddhism, and the Mount Hiei establishment became the principal Buddhist scholarly-monastic center of pre-modern Japan, producing many of the founders of subsequent Japanese Buddhist schools (including Hōnen 法然 of Pure Land, Shinran 親鸞 of Jōdo Shinshū, Eisai 榮西 of Rinzai Zen, Dōgen 道元 of Sōtō Zen, and Nichiren 日蓮 of Hokke / Nichiren Buddhism).
He was posthumously titled Dèngyō Daishi 傳教大師 (“Great Master of the Transmission of the Teaching”) in 866 CE — making him the first Japanese Buddhist figure to receive an imperial daishi title.
Source: Paul Groner, Saichō: The Establishment of the Japanese Tendai School (Hawai’i, 1984; reprinted 2000); auto-prefaces of KR6s0105 and KR6s0106; standard Japanese Tendai-school biographical sources.