Ayutthaya, the capital of the Thai Kingdom was found by U-Thong King in 1350. Ayutthaya as an island is formed by the gathering of three rivers, the Chao Phraya, the Pasak, and the Loburi and surrounded by rice terraces. It is easy to see why the Ayutthaya area was settled prior to this date since the site offered a variety of geographical and economic advantages. The Thai kings of Ayutthaya became powerful in the 14th and 15th centuries, taking over U-Thong, Lopburi, and Ayutthaya.

King U-Thong and his immediate successors expanded Ayutthaya's territory, especially northward towards Sukhothai and eastward towards the Khmer capital of Angkor. The greater size of government could not remain the same as during the days of King Ramkhamhaeng. The society during the Ayutthaya period was strictly hierarchical. There were, roughly, three classes of people king at the top of scale. At the bottom of social scale were commoners and the slaves.

In the early 16th century, the European visited Ayutthaya, and a Portuguese embassy was established in 1511. Portugal's powerful neighbor Spain was the next European nation to arrive in Ayutthaya forward the end of the 16th century. In he early 17th century they saw the arrival of two northern European, the Dutch and the British, and France in 1662.

on this subject: WHC documentation about this site