Prehistory: The earliest known inhabitation of present-day Thailand dates to the Paleolithic period, about 20,000 years ago. Archaeology has revealed evidence of prehistoric inhabitants in the Khorat Plateau in the northeast, who may have forged bronze implements as early as 3000 B.C. and cultivated rice during the fourth millennium B.C.

Early History: In the ninth century B.C., Mon and Khmer people established kingdoms that included large areas of what is now Thailand. Much of what these people absorbed from contacts with South Asian peoples—religious, social, political, and cultural ideas and institutions—later influenced the development of Thailand’s culture and national identity. In the second century B.C., the Hindu-led state of Funan in present-day Cambodia and central Thailand had close commercial contact with India and was a base for Hindu merchant-missionaries. In the southern Isthmus of Kra, Malay city-states controlled routes used by traders and travelers journeying between India and Indochina (present-day Cambodia, Laos, and Vietnam).

Nanchao Period (650–1250): Located on the southwestern border of China’s Tang empire (A.D. 618–907), Nanchao served as a buffer for and later rival to China. The Tai, a people who originally lived in Nanchao, migrated into mainland Southeast Asia over a period of many centuries during the first millennium A.D.

Sukhothai Period (1238–1438): In 1238 a Tai chieftain, Sri Intraditya, declared his independence from Khmer overlords and established a kingdom at Sukhothai in the Chao Phraya Valley in central Thailand. The people of the central plain took the name Thai, which means “free,” to distinguish themselves from other Tai people still under foreign rule. The Kingdom of Sukhothai conquered the Isthmus of Kra in the thirteenth century and financed itself with war booty and tribute from vassal states in Burma, Laos, and the Malay Peninsula. During the reign of Ramkhamhaeng (Rama the Great, r. 1279–98), Sukhothai established diplomatic relations with the Yuan Dynasty (1279–1368) in China and acknowledged China’s emperor as its nominal overlord. After Ramkhamhaeng’s death, the vassal states gradually broke away; a politically weakened Sukhothai was forced to submit in 1378 to the rising new Thai Kingdom of Ayutthaya and was completely absorbed by 1438.

During and following the Sukhothai period, the Thai-speaking Kingdom of Lan Na flourished in the north near the border with Burma. With its capital at Chiang Mai, the name also sometimes given to this kingdom, Lan Na emerged as an independent city-state in 1296. Later, from the sixteenth to eighteenth centuries, Lan Na came under the control of Burma.

Ayutthaya Period (1350–1767): The city-state of Ayutthaya was founded in 1350 and established its capital in 1351 on the Chao Phraya River in central Thailand, calling it Ayutthaya, after Ayodhaya, the Indian city of the hero Rama in the Hindu epic Ramayana. In 1360 Ramathibodi (r. 1351–69) declared Theravada Buddhism as the official religion and compiled a legal code based on Hindu legal texts and Thai custom that remained in effect until the late nineteenth century.

Ayutthaya became the region’s most powerful kingdom, eventually capturing Angkor and forcing the Khmer to submit to Thai suzerainty. Rather than a unified kingdom, Ayutthaya was a patchwork of self-governing principalities and tributary provinces ruled by members of the royal family who owed allegiance to the king. The king, however, was an absolute monarch who took on god-like aspects. This belief in a divine kingship continued until the eighteenth century. The kingdom became increasingly sophisticated as new social, political, and economic developments took place.

In 1511 Ayutthaya received its first diplomatic mission from the Portuguese, who earlier that year had conquered the state of Malacca to the south. Ayutthaya concluded trade treaties with Portugal in 1516 and with the Netherlands in 1592 and established commercial ties with Japan and England in the seventeenth century. Thai diplomatic missions also went to Paris and The Hague. When the Dutch used force to extract extraterritorial rights and freer trade access in 1664, Ayutthaya turned to France for assistance in building fortifications. In addition to construction engineers, French missionaries and the first printing press soon arrived. Fear of the threat of foreign religion to Buddhism and the arrival of English warships provoked anti-European reactions in the late seventeenth century and ushered in a 150-year period of conscious isolation from contacts with the West.

After a bloody dynastic struggle in the 1690s, Ayutthaya entered what some historians have called its golden age—a relatively peaceful period in the second quarter of the eighteenth century when art, literature, and learning flourished. The rising power of Burma led to a Burmese invasion of Ayutthaya and the destruction of its capital and culture in 1767. Only a Chinese attack on Burma kept the chaotic Thai polity from Burmese subjugation.

Thon Buri Period (1767–82): The Thai made a quick recovery under the leadership of a half-Chinese military commander, Phraya Taksin. Taksin had escaped from the besieged Ayutthaya and organized resistance to the Burmese invaders, eventually driving them out. Taksin declared himself king and established a new capital at Thon Buri, a fortress town across the river from modern Bangkok. By 1774 Taksin had annexed Lan Na and reunited Ayutthaya in 1776. He was deposed and executed in 1782, however, by his ministers, who invoked interests of the state over Taksin’s claim to divinity.

Early Chakri Period (1782–1868): Another general, Chakri, assumed the throne and took the name Yot Fa (or Rama I, r. 1782–1809). Yot Fa established the ruling house that continues to the present. The court moved across the river to the village of Bangkok, the kingdom’s economy revived, and what remained of the artistic heritage of Ayutthaya was restored. The Kingdom of Bangkok consolidated claims to territory in Cambodia and the Malayan state of Kedah while Britain annexed territory in an area that had been contested by the Thai and the Burmese for centuries. Subsequent treaties—in 1826 with Britain and in 1833 with the United States—granted foreign trade concessions in Bangkok. The kingdom’s expansion was halted in all directions by 1851.

The reign of King Mongkut (Rama IV, r. 1851–68) marked a new opening to the Western nations. To avoid the humiliations suffered by China and Burma in their wars with Britain and the resulting unequal treaties, Bangkok negotiated and signed treaties with Britain, the United States, France, and other European countries between 1855 and 1870. As a result, commerce with the West increased and, in turn, revolutionized the Thai economy and connected it to the world monetary system. Foreign demands for extraterritoriality convinced Mongkut that legal and administrative reforms were needed if Siam (as the Thai kingdom was officially known from 1855 to 1939 and from 1946 to 1949; prior to then, the Thai traditionally named their country after the capital city) were to be treated as an equal by the Western powers. Monkut’s death in 1868 postponed further reforms, however.

Reign of Chulalongkorn, Reforms, and War (1868–1932): Real reform occurred during the reign of Chulalongkorn (Rama V, r. 1868–1910). After his formal enthronement in 1873, he announced reforms of the judiciary, state finance, and the political structure. An antireform revolt was suppressed in 1874, after which Chulalongkorn embarked on less radical approaches. In time, he ordered the gradual elimination of slavery and corvée labor. He introduced currency-based taxes and a conscription-based regular army. In 1893 a centralized state administration replaced the semifeudal provincial administration. The regime established European-style schools for children of the royal family, and sent government officials, promising civil servants, and military officers to Europe for further education. The first railroad line was opened between Bangkok and Ayutthaya in 1897, and it was extended farther north in 1901 and 1909. To the south, rail connections were made in 1903, linking with British rail lines in Malaya.

During this time, British and French colonial advances in Southeast Asia posed serious threats to Siam’s independence and forced Siam to relinquish its claims in Cambodia, Laos, and the northern Malay states. Although much diminished in territory by the 1910s, Siam preserved its independence, and the kingdom served as a buffer state between the British and French colonies. During this time, anti-Chinese sentiments came to the fore. About 10 percent of the population was Chinese, and ethnic Chinese largely controlled many government positions, the rice trade, and other enterprises, much to the resentment of the native Thai.

Siam joined the Allies in declaring war against Germany during World War I (1914–18) and a small expeditionary force to the European western front. These actions won Siam favorable amendments to its treaties with France and Britain at the end of the war. Siam also gained, as spoils of war, impounded German ships for use in its merchant marine. Siam took part in the Versailles peace conference in 1919 and was a founding member of the League of Nations.

The Emergence of Constitutional Rule (1932–41): A bloodless coup d’état in 1932, engineered by a group of Western-oriented and nationalist-minded government officials and army officers, ended the absolute monarchy and ushered in a constitutional regime. The first parliamentary elections were held in November 1933, confirming Minister of Finance Pridi Phanomyong’s popularity, but Luang Plack Phibunsongkhram (Phibun) used his considerable power as minister of defense to assert the superior efficiency of the military administration over the civilian bureaucracy. In 1938 Phibun succeeded as prime minister, with Pridi continuing with the finance portfolio. The Phibun administration promoted nationalism and in 1939 officially changed the nation’s name from Siam to Muang Thai (Land of the Free), or Thailand. Foreign-owned businesses (mostly Chinese) were heavily taxed, and state subsidies were offered to Thai-owned enterprises. The people were encouraged to emulate European-style fashions. Betel chewing was prohibited, and opium addicts were prosecuted. Irridentist claims for lost territories in Cambodia and Laos were revived amidst new anti-French sentiment. Phibun cultivated closer relations with Japan as a model for modernization and a challenge to European power.

Thailand During World War II (1941–45): After World War II broke out in Europe (1939–45), Japan used its influence with the Vichy regime in France to obtain territorial concessions for Thailand in Laos and Cambodia. The war for Thailand began in earnest on December 8, 1941, when Thai and Japanese troops clashed on the Isthmus of Kra. Bangkok acceded to Japan’s demands that its troops be permitted to cross the isthmus to invade Burma and Malaya. In January 1942, Phibun signed a mutual defense pact with Japan and declared war against Britain and the United States. Seni Pramoj, the anti-Japanese Thai ambassador to Washington, refused to deliver the declaration of war, and the United States refrained from declaring war on Thailand. Seni organized a Free Thai movement, and, with U.S. government support, Thai personnel were trained for anti-Japanese underground activities. In Thailand, Pridi ran a clandestine movement that, by the end of the war, with Allied aid had armed more than 50,000 Thai to resist the Japanese. During the early war years, Phibun was rewarded for his cooperation with Tokyo with the return of further territory that had once been under Thai control. Japan stationed some 150,000 troops in Thailand and built the infamous “death railway” across the River Kwai and through Thailand using Allied prisoners of war. The Allies bombed Bangkok during the war, and public opinion and the civilian political leaders forced Phibun out of office in June 1944.

Civilian Government (1944–47): Shortly after the war, Seni Pramoj briefly served as prime minister. In May 1946, a new constitution was promulgated. It called for a bicameral legislature with a popularly elected lower house and an upper house elected by the lower house. The name Siam was officially restored. The 1946 elections set the stage for Pridi’s accession to the prime minstership. However, two weeks after the election Pridi was accused of being implicated in the untimely death of King Ananda Mahidol (Rama VIII, r. 1935–46), and he resigned and left the country. The new king, Bhumibol Adulyadej (Rama IX, r. 1946– ), who was born in Cambridge, Massachusetts, in 1927, had spent the war in Switzerland and returned there after a brief first visit to Thailand in 1945. He did not return to Bangkok to take up his kingly duties until 1951, following a government-engineered coup.

Return to Military Rule (1947–73): The civilian government’s failure eventually led to the restoration of the Phibun military faction. Phibun had been arrested in 1945 as a war criminal but was released soon afterward. A coup in November 1947 ousted the civilian leaders, and Phibun took over as prime minister in April 1948. During his second government (1948–57), Phibun restored the use of the name Thailand, reintroduced legislation to make Thai social behavior conform to Western standards, improved secondary education, and increased military appropriations. Phibun’s traditional anticommunist position led to Thailand’s continued recognition of Taiwan, and he supported the French in their actions against communist insurgents in Indochina. Thailand also provided ground, naval, and air units to the UN forces fighting during the Korean War (1950–53; Thai forces continued to serve in South Korea until 1972). Phibun brought Thailand into the new Southeast Asia Treaty Organization (SEATO) in 1954. In 1955 SEATO’s headquarters was established in Bangkok, and Thailand offered the United States the use of Thai military bases. In an attempt to generate popular support, Phibun articulated a policy of democracy, but he was deposed in a bloodless coup in September 1957.

Military-controlled government continued between 1957 and 1967. There was talk under Prime Minister Sarit Thanarat of a “restoration” of the king, and a strong popular affection for the monarchy arose. The regime emphasized the kingdom’s Buddhist heritage in an effort to gain support from monks for government programs. Anticommunism continued to influence Thailand’s foreign affairs, and in 1961 Thailand, the Philippines, and newly independent Malaya (since 1963, Malaysia) formed the Association of Southeast Asia (ASA). In 1967 Thailand became a founding member of the Association of Southeast Asian Nations (ASEAN), a broader regional cooperative organization that replaced the ASA. At the same time, Prime Minister Thanom Kittikachorn decided to shorten the timetable for the country’s transition from the military-dominated leadership structure to a popularly elected government.

In June 1968, a new constitution was proclaimed, but martial law, which had been imposed in 1958, remained in effect. Party politics resumed in 1968, and Thanom’s United Thai People’s Party carried the February 1969 National Assembly elections. The new government, however, had to respond to numerous issues: a Muslim insurgency in southern Thailand, communist guerrillas operating in jungle areas north of the Thai-Malaysia border, the successes of communist forces in Vietnam and Laos, and other regional unrest and protests against the government. In November 1971, Thanom carried out a coup against his own government, thereby ending the three-year experiment in parliamentary democracy. The constitution was suspended, political parties were banned, and the military took full charge in suppressing opposition.

Transition to Democratic Rule (1973–76): The stern moves by the Thanom regime led to popular dissatisfaction among university students and organized labor, accompanied by growing anti-U.S. sentiments. Some feared Thanom would even overthrow the monarchy and establish a republic. In a demonstration on October 13, 1973, some 250,000 people pressed their grievances against the government. The following day, troops fired on the demonstrators, killing 75 of them. King Bhumibol took a rare direct role, forcing the cabinet’s resignation; Thanom and his close colleagues were allowed to leave the country secretly. Thammasak University president Sanya Dharmasakti was appointed interim prime minister, and it was he who fully credited the student movement with bringing down the military dictatorship. A new constitution went into effect in October 1974, providing for a popularly elected House of Representatives. The elections were inconclusive, and conservative Seni Pramoj eventually formed a government that lasted less than a month. His brother, Kukrit Pramoj, then put together a more acceptable centrist coalition that lasted until January 1976. Seni returned as prime minister but only until October 1976, when security forces suppressed violent student demonstrations, and Seni was ousted. A military junta took control of the government, declared martial law, annulled the constitution, banned political parties, and strictly censored the media.

Military Rule and Limited Parliamentary Government (1976–92): The new government, led by Prime Minister Thanin Kraivichien, a strident anticommunist, was more repressive in many ways than the earlier military regimes. Strict censorship continued, and the regime tightly controlled labor unions and purged suspected communists from the civil service and educational institutions. As a result, many students joined the communist insurgency. Thanin was replaced in 1977 by General Kriangsak Chomanand. He promulgated a new constitution in December 1978 with a popularly elected House of Representatives and an appointed Senate, but the military controlled cabinet and Senate appointments. Economic instability, however, brought down the Kriangsak government in March 1980. The new prime minster, General Prem Tinsulanonda, commander in chief of the army and minister of defense, came to power by consensus among key politicians. He gave civilians a greater role in government by appointing civilians to his cabinet. A coup attempt in 1981 weakened Prem’s government, and there was continual dissension among the civilian members of the government. Despite student and farmer demonstrations, Prem was reappointed as prime minister in April 1983. He survived a coup attempt in September 1985 and elections in July 1986. Prem was succeeded as prime minister following elections in July 1988 by General Chatichai Choonhavan, the leader of a multiparty coalition. The following years saw a series of military-led governments, efforts to reform, coups, new elections, and coalition party politics. Reforms were introduced in the business sector, the government allowed increased foreign investment, and relations with Cambodia, Laos, and Vietnam improved. Charges of corruption and abuse of power abounded, however, and Chatichai was removed from power in a bloodless coup in February 1991.

Multiparty Democracy, Since 1992: In March 1992, with a new constitution in hand and new elections held, General Suchinda Kraprayoon, one of the February 1991 coup leaders, became prime minister and leader of a five-party coalition. When those parties withdrew their support, Suchinda resigned in May 1992, and Anand Panyarachun, a civilian who had served as acting prime minister between March 1991 and March 1992, was named prime minister. Anand embarked on new reform measures, but he was replaced after the September 1992 elections by Democratic Party (Phak Prachatipat) leader Chuan Leekpai, the head of a four-party coalition. Chuan’s government pushed through constitutional amendments that provided for more wide-ranging democratic practices, enlarged the House of Representatives, reduced the size of the appointed Senate, lowered the voting age from 20 to 18 years of age, guaranteed equality for women, and established an administrative court. In January 1985, the Thai Nation Party (Phak Chat Thai) won the largest number of House seats, and its leader, Banharn Silapa-Archa, headed the new coalition government. In March 1996, Banharn appointed the members of the new Senate; unlike earlier Senates, most members were civilians instead of military officers. The failure of his coalition, however, led to new elections and a new six-party coalition government in November 1996 led by General Chavalit Yongchaiyudh, head of the Phak Khwam Wang Mai (New Aspiration Party).

Chavalit made key economic portfolio appointments to his cabinet, but he failed to implement the austere fiscal policies needed to revive a weak economy. In mid-1997 a major financial crisis ensued, the baht—Thailand’s currency—was devalued, the Central Bank governor resigned, and widespread protests took place. The government announced austerity measures, and the International Monetary Fund (IMF) intervened, but the economy continued to deteriorate. Despite a new constitution promulgated in October 1997, confidence in Chavalit continued to slide, and elections in November returned Chuan Leekpai to the prime ministership as head of a seven-party coalition. This transfer of power without military intervention, from one elected leader to another, represented a major breakthrough in the development of democratic processes in Thailand. The baht continued to devalue, however, and social unrest recurred. By the summer of 1998, the economy had become more stable, although investigations into banking practices continued to uncover mismanagement and irregularities. With assistance from the IMF, Thailand gradually regained macroeconomic stability.

The first-ever elections to the Senate were held in 2002, and, in January 2001, one party—the Phak Thai Rak Thai (Thai Loves Thai Party)—won an absolute majority in the House of Representatives. Because of widespread allegations of illegal election practices, new polling took place in February in some constituencies. The Thai Rak Thai, having merged with another party since the January election, still won the absolute majority of seats, but a coalition government—with the New Aspiration Party and Chat Thai—was established. Police Lieutenant Colonel Thaksin Chinnawat became prime minister. The Thai Rak Thai was further strengthened in 2002 when it absorbed many members of the New Aspiration Party.

Thaksin set out to stabilize several problematic areas. One was to launch a major antidrug campaign. Some 2,275 people were killed in a three-month period ending in April 2003, and the government claimed to have eradicated 90 percent of Thailand’s drug problem. In October 2004, the government launched a second antidrug campaign. Another problem confronting the kingdom was terrorist violence, primarily in the south. In 2002 several police officers were killed, bombs were detonated when the minister of interior toured the violence-prone area, and five schools suffered damage from arsonists. The Thai military attributed these actions to a group thought to be an al Qaeda affiliate and arrested suspected members of Jemaah Islamiah (Community of Islam) in June 2003. They confessed to plotting attacks on embassies in Bangkok and tourist sites. Further arsons and bombings occurred, and attacks on police and army bases in 2004 heightened the terrorist threat. In 2004 alone, more than 500 people died as a result of insurgent and terrorist violence in the south. This loss of life was exacerbated when a massive tsunami hit the Andaman coast on December 26, 2004, killing more than 5,300 Thai and foreigners and leaving another 2,900 reported missing.

In February 2005, the Thai Rak Thai won a 75 percent majority in the House of Representatives elections, and, for the first time, a single-party government was formed. Thaksin continued as prime minister.