What is "zhangzhung"

Zhangzhung or Shangshung was an ancient culture and kingdom of western and northwestern Tibet, which pre-dates the culture of Tibetan Buddhism in Tibet. Zhangzhung culture is associated with the Bon religion, which in turn, has influenced the philosophies and practices of Tibetan Buddhism. Zhangzhung people are mentioned frequently in ancient Tibetan texts as the original rulers of central and western Tibet. Only in the last two decades have archaeologists been given access to do archaeological work in the areas once ruled by the Zhangzhung.

Recently, a tentative match has been proposed between the Zhangzhung and an Iron Age culture now being uncovered on the Changtang plateau of northwestern Tibet.