Not a single story
Buddhism did not enter the Himalaya at one moment, by one route or through one teacher. It arrived in stages, along several valleys and from different directions, and it took different forms in different places. The Kathmandu Valley, the Tibetan plateau, Ladakh, Sikkim and Bhutan each have their own traditions of how the Dharma came to them. This article offers a general outline. Where dates and attributions are uncertain or differ between sources, it says so, and readers who need precision should consult scholarly works.
Early roots in the plains
The Buddha lived and taught in the middle Ganges plain and its northern edge, and the earliest Buddhist communities were based there, not in the mountains. Over the following centuries the teachings spread widely; the part played by the emperor Ashoka in the third century BCE is described under Emperor Ashoka, and the overall picture under spread of Buddhism. Later Buddhist chronicles from Sri Lanka say that missionaries were sent to several regions, including a mountain region called Himavanta in some accounts. The identification of that name with particular places and the historical detail of those accounts are matters scholars still discuss, so it is safest to treat them as tradition.
Archaeological and textual evidence indicates that Buddhism was present in the Kathmandu Valley and nearby hills in the first millennium CE. Newar Buddhism, which developed there, preserved Sanskrit texts and a tradition of monastic compounds and household ritual that remain distinctive today. The history of Buddhism in the region now called Nepal is covered further in history of Buddhism in Nepal.
Buddhism reaches Tibet
According to Tibetan historical tradition, Buddhism became established under the early kings of the Tibetan empire between roughly the seventh and ninth centuries CE. The king Songtsen Gampo is traditionally credited with beginning the process, and temples such as the Jokhang are linked with his reign; the details are discussed under Buddhism reaches Tibet. Chinese and Nepali princesses are said in tradition to have brought Buddha images. Modern historians treat the later, more elaborate versions of these stories cautiously.
A major moment in the same story is the reign of Trisong Detsen in the later eighth century. Tradition says he invited the Indian scholar Shantarakshita and the tantric master Padmasambhava, and that Samye, often described as the first monastery in Tibet, was founded in that period. The role and life of Padmasambhava are known largely through later tradition, which has attached many legends to him. His importance in Nyingma lineage is considerable, and his name is linked with meditation sites and hidden valleys across the range, including the beyul hidden valleys that appear in the pillar on sacred geography.
Fragmentation and revival
After the decline of the Tibetan empire in the ninth century, the old order broke up, and Buddhist institutions went through a difficult and poorly documented period. From around the late tenth and eleventh centuries, a revival began, sometimes called the later spread of the teachings. Translators travelled to India and Kashmir to bring back texts, and Indian teachers came north. The Bengali scholar Atisha is traditionally said to have arrived in Tibet in the eleventh century, and his influence is acknowledged by several schools.
During these centuries the major Tibetan Buddhist schools took shape. The Sakya school is associated with the monastery of that name, founded in the late eleventh century. The Kagyu, with several sub-branches, traces itself to teachers who travelled to India and returned. The Gelug school developed from the reforms of Tsongkhapa in the fourteenth and fifteenth centuries. For overviews see Tibetan Buddhist schools, Kagyu lineage, Sakya lineage and Gelug school. How these schools differ is a matter for each tradition to explain, and this site does not rank them.
Spreading along the range
From the plateau, Tibetan Buddhism spread east and west along the mountains. In the west, Ladakh and neighbouring valleys came under strong Buddhist influence, with monasteries in the region and lineages connected to Tibetan schools; see Ladakh pilgrimage. Western Tibet, in the kingdom of Guge, was an important centre of the later spread, associated with translators and with Atisha’s invitation, and it is touched on under western Tibet Guge.
In the south and east, Buddhism reached Sikkim and Bhutan. In Bhutan the Drukpa Kagyu school became dominant after the arrival of the teacher Zhabdrung Ngawang Namgyal in the seventeenth century, and Padmasambhava is also traditionally linked with central valleys; see Drukpa Kagyu and central Bhutan Bumthang. Sikkim’s Buddhist tradition is generally dated to the seventeenth century in its formal beginnings, with earlier associations in local legend. In the high valleys of Nepal such as Mustang and Dolpo, Tibetan-linked Buddhism and older practices coexist, as described in Mustang and Dolpo Buddhism.
What continued and what changed
In the twentieth century, political changes in Tibet led many monks, nuns and lay people to leave, and exile communities were established in India, Nepal and Bhutan, and later in other countries. As a result, several Himalayan towns became active centres of Tibetan Buddhist teaching and scholarship. Monasteries in Tibet itself have had a different history, with periods of destruction and of limited restoration. Accounts of recent history differ in emphasis, and it is best to read several sources.
Planning around the history
Many of the sites mentioned here are at high altitude or in regions where travel rules change, including permit requirements for foreigners. Check current official sources and government travel advice, consult a doctor about altitude, and follow local guidance on etiquette. This site gives general information only and does not speak for any tradition. The idea that each place carries layers of this history is part of why pilgrims value them.