The Great Perfection (Rdzogs chen) is one of the most important tantric traditions to develop in Tibet, but much of its early history has been obscured by the tradition's visionary narratives of revelation, concealment, and excavation regarding its core scriptures. In addition, the over-reliance on the rubric "Great Perfection" itself obscures a broad diversity of distinct traditions, each with its own distinct rubric of self-identification and often quite divergent characteristics. This includes at the most general level the Three Series (Sde gsum,/i>), Four Cycles (Skor bzhi), Crown Pith (Spyi ti), and Ultra Pith (Yang ti). The present essay utilizes a simple hermeneutic of two trajectories – labeled "pristine" and "funerary," respectively – to offer a developmental history of these movements in broad strokes from the eighth to fourteenth century. In doing so, it interprets the major variants of the Great Perfection historically in terms of their interrelations via development, influence, and criticism. (Than Garson 2005-09-22)