Numerous ethnic groups inhabit Bhutan, with the Ngalop people who speak the Dzongkha language being a majority of the Bhutanese population.
[5] Van Driem (1993) indicates the Sharchop and closely related aboriginal Monpa (Menba) are descendants of the plurality ethnicity of Bhutan and the principal pre-Tibetan (pre-Dzongkha) peoples of that country.
Although long the biggest single ethnic group in Bhutan, the Sharchop have been largely assimilated into the Tibetan-Ngalop culture.
The government traditionally attempted to limit immigration and restrict residence and employment of Nepalese to the southern region.
Some are culturally and linguistically part of the populations of West Bengal or Assam and have embraced the Hindu system of endogamous groups ranked by hierarchy and practice wet-rice and dry-rice agriculture.
They include the Brokpa, Lepcha, and Doya tribes as well as the descendants of slaves brought to Bhutan from similar tribal areas in India.
Some like the Black Mountain Monpa are said to represent the aboriginal people of Bhutan, while some like the Brokpa probably originally migrated from Tibet.
Together, the Ngalop, Sharchop, and tribal groups constituted up to 72 percent of the population in the late 1980s according to official Bhutanese statistics.
Perceiving a lack of allegiance to the state on the part of Tibetans, the government decided in 1979 to expel those who refused residency.
Although Bhutan traditionally welcomed refugees—and still accepted a few new ones fleeing the 1989 unrest in Tibet—official governmental policy in the late 1980s was to refuse more Tibetan refugees.