The first Namkhai Nyingpo was one of the 25 close disciples of Guru Rinpoche and attained full realization through the practice of Yangdak Heruka.
He was able to perform many miracles such as riding on the sun's rays, and was instructed by Yangdak Heruka to write down the whole sadhana for the benefit of future beings.
He also visited India and received teachings from Humkara, and then King Trisong Detsen took him as a teacher and received the entire cycle of Yangdak Heruka teachings from him. It is said that he lived to be 200 years old and was still alive during the time of King Langdarma.
When his activities in that lifetime were complete, he manifested many emanations, although they weren't given the name Namkhai Nyingpo. Among these emanations were the treasure revealers Jangchub Lingpa and Dawa Gyaltsen.
Namkhai Nyingpo was a realized practitioner of Śāntarakṣita’s tradition of Sutrayana "gradualist" Mahayana Buddhism as well as simultaneously being one of the most accomplished Tibetan practitioners of the East Mountain Teaching of Chan Buddhism, which transmits the "subitist" tradition of Mahayana Buddhism.
The 25 disciples of Padmasambhava also called as Guru Rinpoche were instrumental in the spread of Buddha's teachings throughout Tibet. They emerged as masters, having achieved great wisdom, understanding, and success.
These Mahasiddhas are believed to have special future incarnations due to their connection with Padmasambhava's terma treasures.
To this day, these disciples continue to be reborn as Tertons, imparting the teachings of Padmasambhava in a contemporary and authentic way to new .
Nyingma traditional histories consider their teachings to trace back to the first Buddha Samantabhadra (Güntu Sangpo) and Indian mahasiddhas such as Garab Dorjé, Śrī Siṃha and Jñānasūtra.
Traditional sources trace the origin of the Nyingma order in Tibet to figures associated with the initial introduction of Buddhism in the 8th century, such as Padmasambhava, Yeshe Tsogyal, Vimalamitra, Vairotsana, Buddhaguhya and Shantaraksita.
Nyingma teachings are also known for having been passed down through networks of lay practitioners .