The Thais, most historians believe, began migrating from southern China in the early part of the Christian era. At first they formed a number of city-states in the northern part of what is present-day Thailand, in places like Chiang Saen, Chiang Rai and Chiang Mai, but these were never strong enough to exert much influence outside the immediate region. Gradually the Thais migrated further south to the broad and fertile central plains, and expanded their dominance over nearly the entire Indochina Peninsula. Contradictory as it may seem, however, recent archaeological discoveries around the northeast  hamlet of Ban Chiang suggest that the world’s oldest Bronze Age civilization was  flourishing in Thailand some 5,000 years ago.

By the early 1200s the Thais had established small northern city-states in Lanna, Phayao and Sukhothai.  In 1238 two Thai chieftains, Khun Bang Klang Tao and Khun Pha Muang, successfully  rebelled against Khom suzerainty and established the first truly independent Thai kingdom in Sukhothai – a kingdom that was short-lived but of immense cultural importance in the nation’s history.

Sukhothai saw the Thais’ gradual expansion throughout the entire Chao Phraya River basin and the establishment of Theravada Buddhism as the paramount Thai religion. It was here that the first evidence of written Thai was left, along with distinctively Thai styles of art such as painting, sculpture, architecture and literature, which survived after Sukhothai was absorbed by the kingdom of Ayutthaya – a dynamic young kingdom  further south in the Chao Phraya River valley.