Also known as Guru Rinpoche. An Indian Master who along with Shantarakshita and King Trisong Detsen established Tantric Buddhism in Tibet (8th century). He is perhaps most known to westerners in relation to the so-called "Tibetan Book of the Dead." He is widely revered in Tibetan Buddhism, second only to the Buddha Shakyamuni.
"When we are in the physical world, we must learn to be awake from moment to moment. We then live awakened and self-conscious from moment to moment in the internal worlds, both during the hours of the sleep of the physical body and also after death."