Latter during the reign of Tibetan king, Trisong Detsen, he has invited lots of Buddhist masters to Tibet and had important Buddhist texts translation into Tibetan. The great masters like Shantara-kshita, Guru Rinpoche (Padmasambhava), Vimalamitra and many scholars and Sages of India were invited and translated Hinayana, Mahayana and Vajrayana Teachings into Tibetan. Hence Tibet became center for entire range of Buddhist teachings and preserved the teaching of three yanas in an unbroken transmission from ninth century to middle of the twentieth century.
Latter the due to break down of tantaras called Ngak Nyingma and Ngyak Sarma, four major lineages or schools were developed in Tibet namely: 1. Nyingma from old tantaras, and three from new tantaras- 2. Kagyu, 3. Sakya, and 4. Gelluk. Details of four major linages will be elaborate in next post.