Overview
Sukhothai arose in the upper Chao Phraya basin as the first major Tai kingdom. It was founded when the Tai lords Si Inthrathit and Pha Mueang threw off the overlordship of the Khmer Empire (Angkor) — an event traditionally dated 1238. In Thailand it is traditionally regarded as the cradle of the Thai nation, the Thai script, and state Theravada Buddhism.
Key developments
The kingdom peaked under Ram Khamhaeng (r. c. 1279–1298). The Ram Khamhaeng Inscription of 1292 claims a wide tributary network for his realm, and its image of a king accessible to any subject expressed a paternal ideal of kingship. He patronized Sri Lankan-school Theravada Buddhism, and Sangkhalok ceramics became a notable export. After his death, the tributary network shrank quickly.
End and transition
Sukhothai was eclipsed by Ayutthaya, founded in 1351. It became an Ayutthayan vassal by 1378 and was absorbed in 1438. Its ruins, the Sukhothai Historical Park, were inscribed as a UNESCO World Heritage site in 1991.