Thangkas are used by Tibetan Buddhist practitioners to help them develop a close relationship with a meditational deity. They assist the meditator in clearly visualizing particular images. Commissioning a thangka painting is regarded as a way of generating spiritual merit. Thangkas are also used to portray members of a teaching lineage or, in a narrative form, to depict a spiritual master's life, often involving scenes of intricate detail. The earliest instances of Tibetan painting date from the 7th century CE, when Buddhism first had an impact on Tibet, during the reign of King Songtsen Gampo.