The great Indian Buddhist Master Atisha (982-1054 AD) was responsible for reintroducing pure Buddhism into Tibet. Although Buddhism had been introduced into Tibet some two hundred years earlier by Padmasambhava and Shantarakshita, Buddhist practice in the country had largely been destroyed during the anti-Buddhist purges of the Tibetan king, Lang Darma (circa 836 AD), a follower of Bön, the pre-Buddhist religion of Tibet. Revered as one of the great figures of classical Buddhism, Atisha was a key figure in the establishment of the Sarma schools of Tibetan Buddhism.