Sukhothai

Its last great king, Li Thai, who reigned from about 1347 to 1368, answered the challenge with learning rather than arms. He wrote the Trai Phum Phra Ruang, a treatise on the worlds of Buddhist cosmology and the first work of Buddhist philosophy in Thai, and built the great Buddha image at Phitsanulok, where he moved his court in 1363 as pressure from the south grew. It was not enough: Ayutthaya forced Sukhothai into tribute, and in 1378 his son Lue Thai submitted as a vassal.

For sixty years more Sukhothai kept kings of its own, but it was Ayutthaya that settled their quarrels. When the last of them died in 1438, the Ayutthayan king sent his own son to rule as viceroy, and the old kingdom became a province. Its nobility lasted longer than its independence: in 1569 the Burmese conqueror Bayinnaung placed one of them, Maha Thammaracha, on the throne of Ayutthaya itself.