According to the most widely accepted version of its origin, the Siamese state based at Ayutthaya in the valley of the Chao Phraya River rose from the earlier, nearby kingdoms of Lavo (at that time still under the Khmer control) and Suphannaphoom (Suvarnabhumi). One source says that, in the mid-fourteenth century, due to the threat of an epidemic, King U Thong moved his court south into the rich floodplain of the Chao Phraya on an island surrounded by rivers,[note 2] which was the former seaport city of Ayothaya, or Ayothaya Si Raam Thep Nakhon, the Angelic City of Sri Rama. The new city was known as Ayothaya, or Krung Thep Dvaravadi Si Ayothaya. Later it became widely known as Ayutthaya, the Invincible City.[2]
Other sources say that King Uthong was a rich merchant of Chinese origin from Phetchaburi, a coastal city in the south, who moved to seek fortune in Ayothaya city. The name of the city indicates the influence of Hinduism in the region. It is believed that this city is associated with the Thai national epic Ramakien, which is a southeastern version of Hindu epic Ramayana.