Longchen Rabjam Drimé Özer (), commonly abbreviated to Longchenpa (1308–1364, an honorific meaning "The Vast Expanse") was a Tibetan scholar-yogi of the Nyingma school ('Old School') of Tibetan Buddhism. According to tibetologist David Germano, Longchenpa's work led to the dominance of the Longchen Nyingthig lineage of Dzogchen (Great Perfection) over the other Dzogchen traditions. He is also responsible for the scholastic systematization of Dzogchen thought within the context of the wider Tibetan Vajrayana tradition of philosophy which was highly developed at the time among the Sarma schools. Germano also notes that Longchenpa's work is "generally taken to be the definitive expression of the Great Perfection with its precise terminological distinctions, systematic scope, and integration with the normative Buddhist scholasticism that became dominant in Tibet during the thirteenth and fourteenth centuries." Longchenpa is known for his voluminous writings, including the highly influential Seven Treasuries and his compilation of Dzogchen scripture and commentaries, the Nyingthig Yabshi (The Inner Essence in Four Parts). Longchenpa was also a terton (treasure revealer) and some of his works, like the Khadro Yangtig, are considered terma (revealed treasure texts). Longchenpa's oeuvre (of over 270 texts) encapsulates the core of Nyingma thought and praxis and is a critical link between the school's exoteric (or sutra) and esoteric (i.e. tantric) teachings. Longchenpa's work also unified the various Dzogchen traditions of his time into a single system. Longchenpa is known for his skill as a poet and his works are written in a unique literary voice which was widely admired and imitated by later Nyingma figures. Longchenpa was the abbot of Samye, one of Tibet's most important monasteries and the first Buddhist monastery established in the Himalayas. However, he spent most of his life travelling or in retreat. Biography Youth Longchen Rabjam was born in 1308 in a village in the Dra Valley in Yuru, U-Tsang. He was born to the Nyingma lama Lopon Tsensung, a descendent of the Rog clan. Longchenpa's mother died when he was nine and his father died two years after. After being orphaned, he entered Samye monastery in 1320 under the Abbot Sonam Rinchen and master Lopon Kunga Ozer. Longchenpa was an avid student with a great capacity for memory. In 1327, Longchenpa moved to the Kadam monastic college of Sangpu Neutok, the most esteemed center of learning in Tibet at the time. He stayed for six years at Sangpu, mastering the entire scholastic curriculum