What is "longchenpa"

Longchen Rabjampa, Drimé Özer (Wylie: klong chen rab 'byams pa dri med 'od zer), commonly abbreviated to Longchenpa (1308–1364), was a major teacher in the Nyingma school of Tibetan Buddhism. Along with Sakya Pandita and Je Tsongkhapa, he is commonly recognized as one of the three main manifestations of Mañjuśrī to have taught in Central Tibet. His major work is the Seven Treasures, which encapsulates the previous six hundred years of Buddhist thought in Tibet. Longchenpa was a critical link in the exoteric and esoteric transmission of the Dzogchen teachings. He was abbot of Samye, one of Tibet's most important monasteries and the first Buddhist monastery established in the Himalaya, but spent most of his life travelling or in retreat.