The area of Dvaravati (what is now Thailand) was first inhabited by Mon people who had arrived and appeared centuries earlier. The foundations of Buddhism in central Southeast Asia were laid between the 6th and 9th centuries when a Theravada Buddhist culture linked to the Mon people developed in central and northeastern Thailand. Theravadin Buddhists believe that Enlightenment can be obtained only by one living the life of a monk (and not by a layman). Unlike Mahayana Buddhists, who admit the texts of numerous Buddhas and Bodhisattvas into canon, Theravadans venerate only the Buddha Gautama, the founder of the religion. The Mon Buddhist kingdoms that rose in what are now parts of Laos and Central Plain of Thailand were collectively called Dvaravati. Around the tenth century, the city-states of Dvaravati merged into two mandalas, the Lavo (modern Lopburi) and the Suvarnabhumi (modern Suphan Buri).

The Chao Phraya River in what is now central Thailand had once been the home of the Mon Dvaravati culture, which prevailed from the seventh century to the tenth century.^[11] Samuel Beal discovered the polity among the Chinese writings on Southeast Asia as "Duoluobodi". During the early 20th century archaeological excavations led by George Coedès found Nakhon Pathom Province to be a centre of Dvaravati culture. The culture of Dvaravati was based around moated cities, the earliest of which appears to be U Thong in what is now Suphan Buri Province. Other key sites include Nakhon Pathom, Phong Tuk, Si Thep, Khu Bua and Si Mahosot, amongst others.^[12] The inscriptions of Dvaravati were in Sanskrit and Mon using the script derived from the Pallava alphabet of the South Indian Pallava dynasty.

Dvaravati was a network of city-states paying tribute to more powerful ones according to the mandala political model. Dvaravati culture expanded into Isan as well as south as far as the Kra Isthmus. The culture lost power around the tenth century when they submitted to the more unified Lavo-Khmer polity. Around the tenth century, the city-states of Dvaravati merged into two mandalas, the Lavo (modern Lopburi) and the Suvarnabhumi (modern Suphan Buri).