The Lahu originally come from the Tibetan plateau and migrated gradually to Yunnan. They probably began moving into North Thailand in the 1870s or 1880s under pressure of Chinese domination. The Lahu are a strong independent and very diverse ethnic group who number about 60,000 in Thailand. They are located primarily in Chiang Mai and Chiang Rai provinces, but can also be found in considerable numbers as far south as Tak province. Their settlements are usually remote from roads and towns, due to their strong commitment to the maintenance of their traditional way of life. They probably are the most skilled hunters of all tribal groups. There are five sub-groups: Red, Yellow, Black, White and “Sheleh”. The Black Lahu is the largest sub-group, making up close to 80 per cent of the population. Their language is a Tibeto-Burman language and has various dialects. Black Lahu is the most common spoken dialect. Their language has no traditional script. Three romanizations have been introduced during this century, by Protestant and Roman Catholic missionaries and by Chinese government linguists.