As Buddhist Tantra moved eastward, it did not stop in Tibet. By the eighth and ninth centuries, its ideas and practices were already spreading actively through China, Korea, and Japan.
But in each country, they developed differently.
What Happened in China?
During the Tang dynasty, Indian and Central Asian monks arrived in China, where they translated Tantric texts and taught ritual, mantra, and mandala practices.
Three particularly important figures were Śubhākarasiṃha, Vajrabodhi, and Amoghavajra. They are closely associated with the development of a fully established form of Esoteric Buddhism in eighth-century China.
These practices were used not only for meditation. They could also include rituals for the protection of the state, health, and the well-being of the ruler.
In other words, Tantra was not only of interest to monks — it also became relevant to the imperial court and political power.
What Happened in Japan?
The Japanese monk Kūkai traveled to China, studied Esoteric Buddhism there, and brought its teachings back to Japan in the early ninth century.
This led to the development of the Shingon school, which still exists today. Mount Kōya became one of its most important centers.
Kūkai explained the practice in a particularly systematic way: the practitioner works simultaneously with three dimensions —
body — through mudra, speech — through mantra, mind — through visualization.
These “Three Mysteries” were understood as a way of bringing the practitioner into a more direct relationship with Buddhahood.
What About Korea?
Korea served as an important cultural bridge between China and Japan. Buddhism had reached the Korean peninsula from China centuries earlier, and esoteric practices later became part of Korean Buddhist culture, attracting particular interest from the royal court and aristocracy.
However, in Korea, Tantra did not develop into a separate and internationally famous school comparable to Shingon in Japan.
The key point is this: Buddhist Tantra does not belong only to Tibet.
It developed across large parts of Asia — but in China, Korea, and Japan it took on distinctive forms, histories, and purposes of its own.