Emergence of the Vajrayana (5th century)

Vajrayāna Buddhism, also called Tantric Buddhism, first emerged in eastern India between the 5th and 7th centuries CE. It is sometimes considered a sub-school of Mahayana and sometimes a third major "vehicle" (Yana) of Buddhism in its own right. The Vajrayana is an extension of Mahayana Buddhism in that it does not offer new philosophical perspectives, but rather introduces additional techniques (upaya, or 'skilful means'), including the use of visualizations and other yogic practices. Many of the practices of Tantric Buddhism are common with Hindu tantricism (the usage of mantras, yoga, or the burning of sacrificial offerings). This school of thought was founded by Padmasambhava.
Early Vajrayana practitioners were forest-dwelling mahasiddhas who lived on the margins of society, but by the 9th century Vajrayana had won acceptance at major Mahayana monastic universities such as Nalanda and Vikramashila. Along with much of the rest of Indian Buddhism, the Vajrayana was eclipsed in the wake of the late 12th century Muslim invasions. It has persisted in Tibet, where it was wholly transplanted from the 7th to 12th centuries and became the dominant form of Buddhism to the present day, and on a limited basis in Japan as well where it evolved into Shingon Buddhism.