12th century, Tibet
In this work, Gampopa unified several theories, concepts and teachings that were becoming separated in the various schools arising during this early period of Tibetan Tantric Buddhism.
Mainly, he combined the Mahamudra teachings of
Milarepa and the Naro Chosdrug of
Naropa into a new synthesis.
Having been first educated, in his youth, by the Kadampa, he also assimilated elements of this more monastic strand of teachings into his work.
Guenther, H.V. (trans.) The Jewel Ornament of Liberation by sGam.Po.Pa. London: Rider, 1959. Boston and London: Shambhala, 1971.