Archaeological sites dating of around 5,000 years have been found ago in the northeastern part of Thailand, believed to contain the oldest evidence of the rice cultivation and bronze casting in the whole of Asia. There were tribal groups called the Mon and Khmer that created strong kingdoms that stretched a lot of Thailand. Thai people originally lived and migrated from China to the mainland of Southeast Asia over hundreds of years. The hearing of their existence in the region goes back to the twelfth century A.D. An inscription found in a Khmer temple in Cambodia, already referred to Siam. In 1238, the Thais declared independence from the Khmer kingdom and established a kingdom in Sukothai, which was located in the Valley of Mae Nam Chao Phraya River. The Sukothai kingdom was taken over in the fourteenth century by the kingdom of Ayutthaya. In 1767, the Burmese tried invading the kingdom of Ayutthaya and destroyed the capital city, but two national heroes, Taskin and Chakkri, banished the invaders and reunified the country under the Chakkri Dynasty.
During the centuries of this evolving nation, the Thai national identity was developed around its common language, religion and institution of the monarchy. Early in the 14th century, the Thai language alphabet was formed through Indian and Khmer scripts. Later on in the century, Theravada Buddhism become the official religion of the kingdom, under the famous monarch Ramathibodi, and it has s until maintained itself as the official religion up to the twentieth century, as a head figure in the nation’s cultural and social life.
In 1782 Rama I become king of Thailand, and he moved the capital city across the Chao Phraya River from Thonburi to Bangkok. In 1809 Rama II, the son of King Rama I, took over the throne and ruled until 1824. Where Rama III became the new king, he started to develop trade with China and increase the country’s domestic agricultural production. King Mongkut Rama IV then took the throne in 1851 and he constituted diplomatic relations with European nations yet refraining western colonization. Between 1910 and 1925, King Vajiravudha (Rama VI) initiated compulsory education and other reforms to improve the cultural level of his people.
The Ayutthaya period, established in the mid-14th century and lasting until the Burmese invasion and the fall of Ayutthaya in 1767, was followed by the Ratanakosin period and the ruler became Rama IX. This was when the name of the country changed from Siam to Thailand, which means “freedom”.