Which kingdom was founded by the ancestors of modern Thai people?

The Sukhothai Kingdom is recognized as the first significant kingdom established by the ancestors of modern Thai people, specifically during the 13th century. It is often credited with laying the foundation for what would later become Thailand's distinct cultural identity. The Sukhothai period is notable for the development of the Thai script, advancements in art, and the establishment of important cultural practices that are still prevalent in Thai society today.

This kingdom is also significant as it represents a shift in power from earlier communities to a more centralized and organized kingdom, marking the beginning of the Thai nation-state. The rulers of Sukhothai, particularly King Ramkhamhaeng, are celebrated for their contributions to the Thai language and culture, further solidifying Sukhothai's role as a core part of Thai heritage.

In contrast, while the Ayutthaya, Lanna, and Rattanakosin kingdoms are also crucial to Thai history, they came later and were influenced by the earlier developments made during the Sukhothai period. Each of these later kingdoms builds on the foundation established by Sukhothai but does not represent the origin of the Thai people in the same way.