Recent archaeological evidence suggest that the region known today as Thailand has been inhabited by humans since at least 5,000 years ago. Thai are related to groups originating in southern China, Thais migrated from southern China to mainland Southeast Asia approximately the 10th century AD. Prior to this, Mon, Khmer and Malay kingdoms ruled the area.
According to tradition, in 1238 AD, the Thai community founded the first Thai kingdom, Sukhothai, which marks the foundation of the Sukhothai Period. Called by its leaders "the dawn of happiness", is regarded as the golden era of Thai history, an ideal state rules by benevolent kings.
During the Sukhothai era, King Ramkhamhaeng the Great organized a method of writing which became the basis for modern Thai. Sukhothai increased its influence and expanded for nearly 200 years, however, Sukhothai was overshadowed by the powerful Siamese kingdom of Ayutthaya in the mid-14th century.
Ayutthaya adopted the Khmer cultural influences like customs and rituals; the early part of this age saw Ayutthaya Kingdom extending its control over neighboring Thai principalities.
King Ramathibodi I, the first monarch of the Kingdom of Ayutthaya, made two significant contributions to Thai history:
- The declaration of the Theravada Buddhism as the official religion.
- The compilation of the Dharmashastra, a legal code based on Hindu basis and traditional Thai custom.
During the 17th century, the first formal diplomatic and commercial contacts between Siam and western countries were established.
After more than 400 years of power, in 1767, a Burmese offensive succeeded in capturing Ayutthaya. Thais were regrouped under the leadership of a young general named Phya Taksin who managed to expel the Burmese. General Taksin established Thonburi as the new capital, on the west bank Chao Phraya River and declared himself king in 1769.
In 1782, Taksin supposedly became mad, was deposed and killed. General Chakri himself crowned king Rama I the Great, first king of the Chakri Dynasty, ruling from 1782 to 1809. His first action as king was to transfer the royal capital across the river from Thon Buri to the more defendable Bangkok, starting the Rattanakosin era in the Thai history. Rama II (1809-1824) continued the restoration begun by his ancestor. King Nang Klao, Rama III (1824-1851) re-opened affairs with Western countries and developed business with China.
King Mongkut, Rama IV, (1851-1868) concluded treaties with the British in 1855, with the United States and France in 1856, avoided colonization and established modern Thailand. King Chulalongkorn, Rama V (1869-1910) continued his father's tradition of reorganization, abolishing slavery and improving the public welfare and governmental system. Thailand is the only Southeast Asian country never to have been taken over as a colony, the country’s contemporary name, Prathet Thai or Thailand is a reflect of this, Prathet means “Nation” and Thai means “Free”.
King Vajiravudh, Rama VI (1910-1925) established obligatory education and other educational reforms. In 1932, a bloodless revolution of Westernized intellectuals mounted a successful coup d'état marking the end of the absolute monarchy and the beginning of a new constitutional monarchy. During the reign of King Prajadhipok (1925-1935), Thailand changed from an absolute monarchy to a constitutional monarchy. The king resigned in 1933 and was succeeded by his nephew.
Since then, Thailand experienced multiple changes of government, almost permanent coups d'états before the establishment of a democratic system.
During reign of King Ananda Mahidol, Rama VIII (1935-1946), the country's name was changed from Siam to Thailand; he was assassinated in mysterious circumstances in 1946. The present monarch, King Bhumibol Adulyadej, is King Rama IX of the Chakri Dynasty; is the world's longest-reigning king, he commands great admiration in both Thailand and throughout the rest of the world.
During World War II, Thailand signed a pact with Japan. Following the conflict, however, Thailand becomes a United States collaborator, since 1945 Thailand has had very close affairs with the United States.
Since the 1992 elections Thailand has a democratic system with constitutional changes of administration.
In 1997, Thailand was beat with the Asian financial disaster and the Thai baht for a short instant peaked at 56 baht to the U.S. dollar compared to about 25 baht to the dollar before 1997. Since then, the baht has recovered most of its strength and as of May 23, 2007, is valued at 33 baht to the US dollar.
In September 2006, a rapid and bloodless military coup overthrew the previous democratically voted government, promising elections in late 2007. There has been no hostility and no major military presence in public places, and all services are working normally.
The official calendar in Thailand is based on Eastern version of the Buddhist Era, which is 543 years ahead of the Gregorian (western) calendar. For example, the year AD 2008 is called 2551 BE in Thailand.