More than 12,000 members of the Yong ethnic group live in scattered parts of northern Thailand. They inhabit villages within three provinces: Lamphun (Muang, Pasang, Ban Hong and Mae Tha districts); Chiang Mai and Chiang Rai.
Joachim Schliesinger, in his excellent book Tai Groups of Thailand, quotes a population source of between 240,000 and 320,000 Yong people in Thailand. This high figure is unlikely, since if it were correct the Yong would be one of the largest ethnic groups in northern Thailand. As it is, few people outside of their immediate areas have ever heard of them.
Schliesinger states that the Yong 'are in fact ethnic Lu people who once lived in Muang Yong of today's Shan State of Burma. As is common practice among Tai peoples, the Tai Yong derived their new group name from their location at Muang Yong.... The King of Siam ordered the Chiang Mai rulers to launch several military raids north and west into the [Shan, Khun and Yong] villages and towns to capture the inhabitants and resettle them as war captives to Chiang Mai, Lamphun and Lampang. The largest influx of Yong occurred in 1805, when 10,000 people were taken from Muang Yong to be resettled in northern Thailand.'
The first Yong arrivals in Thailand settled in the Pasang District of Lamphun Province. They named their village Ban Vieng Vong. This remains an active Yong habitation to this day. At Ban Vieng Vong, 'the Yong reinforced ritual power and social stratification. The oldest monastery in Ban Vieng Vong shelters the four guardian spirits of their former Muang Yong in Burma, which they took with them when they were resettled.' The names of these four idols, symbolized as stone white elephants, are suranna, pittiya, lakkhana and thewada. They are considered sacred to the Yong people, who not only worship and appease these spirit beings, but who also see their identity and history as a people intricately bound up with the safe transport of these idols from their original homeland.
The Yong language is a member of the Southwestern Tai linguistic branch. There are numerous languages in this group, with speakers dispersed over a wide geographical area from India to Laos. Most of the Southwestern Tai groups are strong believers in Theravada Buddhism.
Although Buddhism is the chosen religion of the Yong people, their beliefs are heavily mixed with animistic ritual and spirit-worship. The Yong 'honor the spirit of the land and the ancestral spirits and believe in many other spirits of the surroundings. On full moon in June, the villagers flock to the local spirit shrine to make sacrifices. of pig heads, chicken, and nine different kinds of fruit.'
There is now (2019) a report of at least one Christian believer among the Yong. Others are blinded by their deep religious devotion to idols and traditions and in need of much prayer.