In Prachin Buri Province found habitation of ancient community around 2,000 - 2,500 years ago that corresponds to late prehistorical period to prehistorical period (Proto-history) at archaeological site, Ban Krathum Phaeo, Ban Sang District, Ban Nong-O, Dong Phraram Sub-district, Mueang District and Ban Dongmonchai, Prachantakham Sub-district, Prachantakham District

The archaeology that was found such as Indo-Pasific beads, Canelian beads, Agate stone and Quartz stone, steel equipment that represented commerce with near ancient community and India, especially Dongchai village that found Bronze Drum accessories which were antiques of Dong Son Culture related to the ceremony that found in Southern of China and Southeast Asia included Thailand.

The location of the ancient city of Si Mahosot, Khok Peep Sub-district, Si Mahosot District. It is assumed that it was a community before the 11th century. In the area, the community gathered together as a group of farmers into an agricultural village. There was trade and exchange with outside cultures, but no cities with earthworks had yet been built. A moat surrounds the community. At this stage it may have been related to the Funan empire and there was an exchange of trade with sailors from foreign countries. The found evidence represent the influence of the Fuman culture and the influence of the Amaravati Indian culture. Important evidence found includes bas-relief carvings and some sculptures found in this area, namely images of dragons or some Rao at the edge of the Sa Kaeo archaeological site that look similar. The dragon in Indian art, Gupta style Some of the sculptures include the Buddha image found in the pond in front of the Twin Footprints Building. And from the discovery of polished stone tools, it can be inferred that the community is probably related to the prehistoric communities found along the way. The original coastline Bang Pakong River Basin area in Chonburi Province Which began to settle about 5,000 - 1,400 years ago.

It can be concluded that human settlement began in Prachinburi Province. It was a late prehistoric community. The high technology of living was known how to use iron tools and knowing how to store water. Then, social and economic conditions became more complex until entering the 6th-10th centuries, receiving outside culture and entering the historical era. Developed into a community or city known as Dvaravati Cultural Group It dates from the 12th-19th Buddhist centuries.

The emergence of towns during the historical period between the 12th – 19th Buddhist centuries divided Prachinburi Province into two periods:

the first period was prosperous and developed into a contemporary country, and the Dvaravati group of towns in the central region of the country was between the 12th - 16th Buddhist centuries, the second period is a continuation of the first period, but the social, political, and administrative conditions have changed from the original. It is believed that during this period the ancient Khmer culture was introduced. It is mixed with the Dvaravati culture that had flourished before.