Mount Hiei (Enryaku-ji)

Saicho, a young monk dissatisfied with the Buddhism he had studied in the capital, built a small hermitage on Mount Hiei in 788 CE and, after a period of study in China, returned to found it formally as Enryaku-ji, headquarters of the Tendai school he had brought back with him, built around the Lotus Sutra and a comprehensive, syncretic reading of Buddhist teaching. Saicho spent much of his later life petitioning the court for the right to ordain monks on Mount Hiei using a Mahayana ordination platform independent of the older Nara schools, a dispute settled only after his death in 822, when the kaidan, the ordination platform, was finally authorized. That victory mattered more than its narrow procedural content suggests, because it made Mount Hiei the training ground of choice for ambitious monks for the next four centuries, largely free of Nara's institutional control.

Honen, who founded Pure Land Buddhism's Jodo-shu; his student Shinran, who founded Jodo Shinshu; Eisai, who brought Rinzai Zen to Japan; Dogen, founder of Soto Zen; and Nichiren, founder of the school that bears his name, all trained on the mountain before breaking away to found their own schools, so that nearly every major current of later Japanese Buddhism traces at least one root back to Mount Hiei's monastery, even where the schools that grew from it later stood in sharp doctrinal opposition to Tendai itself and to each other.

Mount Hiei's monks were also, for much of the medieval period, an armed political force, maintaining warrior monks, sohei, who intervened repeatedly in the capital's politics and fought rival temples over land and influence. That power ended in 1571, when the warlord Oda Nobunaga, seeking to break the temple's independent authority and end its alliance with his enemies, sent his army up the mountain and burned the complex to the ground, killing, by most accounts, several thousand monks, women and children sheltering there in what remains one of the starkest instances of religious violence in Japanese history.

Rebuilding began under Toyotomi Hideyoshi and continued under the Tokugawa shogunate, which favored Tendai and restored Enryaku-ji as an active monastery, though on a smaller footprint than its medieval extent. The complex today is inscribed on UNESCO's World Heritage List as part of the Historic Monuments of Ancient Kyoto, alongside sites within the city itself. Its most demanding surviving practice is the kaihogyo, the thousand day circumambulation undertaken by a small number of monks over seven years, walking a marked mountain route for as long as nine hours a day during its most intense phases, a practice popularly known outside Japan as the discipline of the marathon monks and understood within Tendai as itself a form of meditation in motion.