Higham states, "U-Thong was occupied for many centuries prior to the development of the Dvaravati state. Radiocarbon determinations from the sites of U-Thong and Chansen suggest that the transition into complex state societies in the Chao Phraya basin took place between about 300-600 AD." A copper inscription from the mid-7th century states, "Sri Harshavarman, grandson of Ishanavarman, having expanded his sphere of glory, obtained the lion throne through regular succession," and mentions gifts to a linga. The site includes a moat, 1,690 by 840 m, and the Pra Paton caitya.[2]: 300, 302, 306–307
It also became the origin of the Ayutthaya Kingdom, as the first King of Ayutthaya, Ramathibodi, was prince of U Thong when the city was struck by an epidemic, prompting him to relocate east and found Ayutthaya.[3]
U Thong district was created with the name Chorakhe Sam Phan in 1905. In 1939 the district was renamed U Thong.[4] In 1944, the government moved the centre of the district from Ban Chorakhe Sam Phan to the area of the ancient city.[5]
^ abHigham, C., 2014, Early Mainland Southeast Asia, Bangkok: River Books Co., Ltd., ISBN9786167339443
^H. R. H. Prince Damrong (1904). "The Foundation of Ayuthia"(PDF). Journal of the Siam Society. 1.0e. Siam Heritage Trust. There is an old city ... called by the people Müang U Thong (the city of King U Thong) and there is a tradition that Thao U Thong reigned over this city until an epidemic broke out and the people died in great numbers. He then abandoned the city and turning to the East looked out for another place to establish the capital; but the epidemic did not abate. He then crossed the Suphan (Tachin) river to escape the ravages of the epidemic, and even at the present time near the Suphan river there is a place called "Tha Thao U Thong" 'i.e.' the crossing of King U Thong.