Many Buddhist from Tibet, as in the case of China, came to India. Buddhist monks from Tibet came to study at the universities of Nalanda, Vikramshila and Odantapuri. As a reciprocation, many Indian Buddhist visited Tibet. In the eighth century AD from Nalanda (a famous centre of learning in ancient Bihar) Buddhist monk Padmasambhava went to Tibet and succeeded in converting the land into Buddhism.
The Pala rulers of Bengal (Bihar was included in Bengal at that time) who were great patrons of Buddhism, contributed a lot to reform Buddhism in Tibet. Vajrayana (Vehicle of Thunderbolt) form of Buddhism was established in Tibet in the eleventh century AD as a result of missions sent from the Vajrayana monastery of Vikramshila in Bihar. Vajrayana is synonymous with Tantric Buddhism. Great Buddhist monk Atish Dipankar from Bengal, who visited Tibet in the 11th century during the reign of Nayapala, is still venerated there.
Many Buddhist works have been translated into Tibetan. Tanjur and Kanjur are the two classical Tibetan translations of Buddhist sacred texts .