The Nashi are thought to have come originally from northwestern China, migrating south toward Tibetan populated regions, and usually inhabiting the most fertile river-side land, driving the other competing tribes farther up the hillsides onto less fertile land. The Nashi, along with Bai and Tibetans, traded over the dangerous overland trading links with Lhasa and India, on the so-called Tea and Horse Caravan routes. They were brought to the attention of the Western world by two men: the American botanist Joseph Rock and the Russian traveller and writer Peter Goullart, both of whom lived in Lijiang and travelled throughout the area during the early 20th century. Peter Goullart's book "Forgotten Kingdom" describes the life and beliefs of the Nashi and neighbouring peoples, while Joseph Rock's legacy includes diaries, maps, and photographs of the region, many of which were published in National Geographic. The two were friends and left the region together when the Communist troops came in.