Twelve centuries after the Buddha attained 'Nirvana', the Tibetan King, Songtsen Gampo ( Sron-bTsan Sgam-Po ) who ruled from 618 to 649 AD.), married Wen Cheng from the court of China's Tang dynasty and Bkrikuti Devi, a Nepalese princess. Under their influence, Buddhism slowly developed in the Central Himalayan and Trans Himalayan region of Tibet, Spiti, Lahaul and Ladakh till it became the prominent faith. A great impetus came when king Trison Detsen ( Khri-Sron-Ide-bTsan ) 755-797 AD.) of Tibet embraced the teachings of Buddha. He sent to India for great masters like Santarakshita and the famous teacher and tantric named Padmasambhava. Under Padmasambhava's influence, Mahayan Buddhism, the Greater Vedic fanned over the world's highest plateaux. Known to the Tibetans as Guru or Orgian Pimpoche, the Precious Master Padamsambhava began the synthesis of Mahayan practises, yogic tantracism and the native Bon religion - retaining a large measure of its nature worship and demonolatry. The combine of ritual, faith and philosophic content created what we recognise today as Vajrayana Buddhism, the Thunderbolt Vehicle.
The 9th century brought a break in the spread of Buddhism learning when the king, Lang Darma rejected it and began supporting the Bon faith. He was murdered by a Buddhist monk, Pal Dorje, and the 10th and 11th centuries witnessed the grand revival og Buddhism learning. It was an age of great teachers - Atisha, Marpa, Rinchensang - po and Milarepa. In 1357 AD., the towering reformer, Tsong Khapa began the religious renewal that emphasised Atisha's teachings and a purity of doctrine. He founded the Geluk - pa sect, the Yellow Hats, who grew to hold considerably sway - and from which the Dalai Lamas were to come. In 1578 AD., a descendent of Chengis - Chengis Khan and ruler of China, had given Sonam Gyatso the title of Ta-le, now written as Dalai - which means the Master of the Ocean of Wisdom. When the kingdom of Guge rose in Western Tibet after the assassination of Lang Darma, it encompassed the present day tract of Spiti, Lahaul, Zanskar and upper Kinnaur. The strong cultural and religious identity of the region dates back to those years.