In 1661 the Jesuits Grueber (d. 1680) and d’Orville (d. 1661) set out from Beijing, where they had trained in geographical surveying methods for their planned trip back overland to Europe. They reached the limits of Qing territory at Xining, where they encountered the end of the Great Wall of China and the gateway through which merchants from India entered China. Leaving Xining, they crossed Tangut territory, ruled by the "Kalmuk" (Kalmyck or Oirad) Mongols who had moved to this region in 1638. Grueber's account describes the clothing of the lay men and women as well as their lamas. He also described and sketched the Potala Palace, Khampa women with their distinctive hair dressing, and the images of the Dalai Lama and the former Oirat ruler Gushri Khan. Kircher, who summarized his reports, altered the illustrations much to Grueber's frustration, but these are the earliest images of lamas and Tibet made by Europeans that survive.The two Jesuits only stayed a couple of months in Lhasa, but they saw enough to report that the Dalai Lama "is worshipped like a divinity, not only by the natives, but by all the subjected kings of Tartary" and that "[l]est he seem to lose his immortality, after his death the lamas search the whole kingdom for a man similar to him in every respect."

Sources: Athanasius Kircher, China Illustrata, 1667 (Bloomington, IN: Research Institute for Inner Asia Studies. 1987), Part II, Ch4, pp. 60-70.
Summary of Grueber's travels and letters: In Clements R Markham, Sir George Bogle; Thomas Manning. Narratives of the mission of George Bogle to Tibet, & of Thomas Manning to Lhasa. London, Trübner and Co., 1876. 295-301.
MacGregor, John. Tibet: a chronicle of exploration. London. 1970, 48-58.
For translations of Grueber's letters: see Thomas Astley, New General Collection of Voyages and Travels, Vol . IV (London 1747), p. 457-462.