Nyingma
The Nyingma tradition is one of the major schools of Tibetan Buddhism and understood as its oldest. It is distinguished particularly for its development of the Dzogchen tradition and an emphasis on terma literature. Centered largely on the teachings of 8th century master Padmasambhava, modern masters of the lineage include Wisdom authors Dudjom Rinpoche, Anyen Rinpoche, and Tulku Thondup Rinpoche.