Of the four principal language families in the Indian subcontinent—Indo-European, Tibeto-Burman, Austroasiatic, and Dravidian—the first two are well represented in the Himalayas. In ancient times, peoples speaking languages from both families mixed in varying proportions in different areas. Their distribution is the result of a long history of penetrations by Central Asian and Iranian groups from the west, Indian peoples from the south, and Asian peoples from the east and north. In Nepal, which constitutes the middle third of the Himalayas, those groups overlapped and intermingled. The penetrations of the lower Himalayas were instrumental to the migrations into and through the river-plain passageways of South Asia. Generally speaking, the Great Himalayas and the Tethys Himalayas are inhabited by Tibetans and peoples speaking other Tibeto-Burman languages, while the Lesser Himalayas are the home of Indo-European language speakers. Among the latter are the Kashmiri people of the Vale of Kashmir and the Gaddi and Gujari, who live in the hilly areas of the Lesser Himalayas. Traditionally, the Gaddi are a hill people; they possess large flocks of sheep and herds of goats and go down with them from their snowy abode in the Outer Himalayas only in winter, returning again to the highest pastures in June. The Gujari are traditionally a migrating pastoral people who live off their herds of sheep, goats, and a few cattle, for which they seek pasture at various elevations. The Champa, Ladakhi, Balti, and Dard peoples live to the north of the Great Himalaya Range in the Kashmir Himalayas. The Dard speak Indo-European languages, while the others are Tibeto-Burman speakers. The Champa traditionally lead a nomadic pastoral life in the upper Indus valley. The Ladakhi have settled on terraces and alluvial fans that flank the Indus in the northeastern Kashmir region. The Balti have spread farther down the Indus valley and have adopted Islam.
Other Indo-European speakers are the Kanet in Himachal Pradesh and the Khasi in Uttarakhand. In Himachal Pradesh most people in the districts of Kalpa and Lahul-Spiti are the descendants of migrants from Tibet who speak Tibeto-Burman languages.
In Nepal the Pahari, speaking Indo-European languages, constitute the majority of the population, although large groups of Tibeto-Burman speakers are found throughout the country. They include the Newar, the Tamang, the Gurung, the Magar, the Sherpa and other peoples related to the Bhutia, and the Kirat. The Kirat were the earliest inhabitants of the Kathmandu Valley. The Newar are also one of the earliest groups in Nepal. The Tamang inhabit the high valleys to the northwest, north, and east of Kathmandu Valley. The Gurung live on the southern slopes of the Annapurna massif, pasturing their cattle as high as 12,000 feet (3,700 metres). The Magar inhabit western Nepal but migrate seasonally to other parts of the country. The Sherpa, who live to the south of Mount Everest, are famed mountaineers. For some 200 years the Sikkim region (now a state in India) and the kingdom of Bhutan have been safety valves for the absorption of the excess population of eastern Nepal. More Sherpa now live in the Darjiling area than in the Mount Everest homeland. At present the Pahari constitute the majority who come from Nepal in both Sikkim and Bhutan. Thus, the people of Sikkim belong to three distinct ethnic groups—the Lepcha, the Bhutia, and the Pahari. Generally speaking, the Nepalese and the Lepcha live in western Bhutan and the Bhutia of Tibetan origin in eastern Bhutan. Arunachal Pradesh is the homeland of several groups—the Abor or Adi, the Aka, the Apa Tani, the Dafla, the Khampti, the Khowa, the Mishmi, the Momba, the Miri, and the Singpho. Linguistically, they are Tibeto-Burman. Each group has its homeland in a distinct river valley, and all practice shifting cultivation (i.e., they grow crops on a different tract of land each year).