The Thonburi Kingdom was a major Siamese kingdom which existed in Southeast Asia from 1767 to 1782, centred on the city of Thonburi, in Siam or present-day Thailand. The kingdom was founded by Taksin, who reunited Siam following the collapse of the Ayutthaya Kingdom, which saw the country separate into five warring regional states. The Thonburi Kingdom oversaw the rapid reunification and reestablishment of Siam as a preeminient military power within mainland Southeast Asia, overseeing the country's expansion to its greatest territorial extent up to that point in its history, incorporating Lan Na, the Laotian kingdoms (Luang Phrabang, Vientiane, Champasak), and Cambodia under the Siamese sphere of influence.
The Thonburi Kingdom saw the consolidation and continued growth of Chinese trade from Qing China, a continuation from the late Ayutthaya period (1688-1767), and the increased influence of the Chinese community in Siam, with Taksin and later monarchs sharing close connections and close family ties with the Sino-Siamese community.
The Thonburi Kingdom lasted for only 14 years, ending in 1782 when Taksin was deposed by a major Thonburi military commander, Chao Phraya Chakri, who subsequently founded the Rattanakosin Kingdom, the fourth and present ruling kingdom of Thailand.
History
Taksin's reunification of Siam
Phraya Tak, personal name Sin, Zheng Zhao (鄭昭) or Zheng Xin (鄭信), was a nobleman of Teochew Chinese descent. By the time of Burmese Invasion of 1765-1767, Phraya Tak had been the governor of Tak and called to join the defense of Ayutthaya. In January 1767, about three months before the Fall of Ayutthaya, Phraya Tak gathered his own forces of 500 followers and broke through the Burmese encirclement to the east. After battling with Burmese scouting forces and some local resistances, Phraya Tak and his retinue settled in Rayong on the eastern Siamese coast. There, Phraya Tak competed with Pu Lan the Phraya Chanthaburi or the governor of Chanthaburi for domination over the eastern coastline. In the famous episode, Phraya Tak ordered all cooking pots in the supplies to be destroyed and then successfully took Chanthaburi in June 1767. Phraya Tak established his dominions of influence on the eastern coast stretching from Bang Plasoi (Chonburi) to Trat.
Ayutthaya fell in April 1767. Due to the intervening Sino-Burmese War, Burma was obliged to divert most of its forces from Ayutthaya to the Chinese front. The Burmese had left a garrison at Phosamton to the north of Ayutthaya under the command of the Mon Thugyi. The Burmese were in control only in Lower Central Siam as the rest of Siam fell into the hands of various warlord regimes that sprang up. In the northeast, Prince Kromma Muen Thepphiphit established himself in Phimai. To the north, Chaophraya Phitsanulok Rueang made his base in Phitsanulok, while the heterodox monk Chao Phra Fang founded a theocratic regime in Sawangkhaburi. To the south, Phra Palat Nu or Chao Nakhon became the leader of Nakhon Si Thammarat (Ligor) regime.
In October 1767, Phraya Tak left Chanthaburi and took his fleet of 5,000 men to the Chao Phraya. He took Thonburi and proceeded to attack the Burmese at Phosamton in November, defeating the Burmese commander Thugyi or Suki. Phraya Tak founded the new Siamese capital at Thonburi and enthroned himself as king there in December 1767. He is colloquially and posthumously known as King Taksin, combining his title Phraya Tak and his name Sin. For strategic reasons, Taksin decided to move the capital from Ayutthaya to Thonburi, making it easier for commerce. Six months after the Fall of Ayutthaya, Taksin managed to reconquer and establish his powers in Central Siam. A Burmese force from Tavoy arrived to attack the Chinese encampment of Bangkung in Samut Songkhram. King Taksin repelled the Burmese in the Battle of Bangkung in 1768.
King Taksin then went on his campaigns against other competing rival regimes to unify Siam. He first moved against Phitsanulok in the north in 1768 but was defeated at Koeichai with Taksin himself got shot at his leg. Thonburi went on to conquer the Phimai regime in the northeast in 1768 and the Nakhon Si Thammarat regime in October 1769. Prince Thepphiphit was executed but Nakhon Nu of Ligor was allowed to live in custody. In the north, Chao Phra Fang conquered and incorporated the Phitsanulok regime in 1768, becoming a formidable opponent of Taksin. In 1770, the forces of Chao Phra Fang penetrated south as far as Chainat. King Taksin, in retaliation, led the Thonburi armies to capture Phitsanulok in August 1770. Thonburi forces continued north to seize Sawangkhaburi. Chao Phra Fang escaped and disappeared from history. With the conquest of the last rival regime by 1770, Taksin's position as the ruler of Siam was assured and Siam was unified at last.
Invasion of Cambodia and Hà Tiên
In the eighteenth century, the port city of Hà Tiên, ruled by the Cantonese Mạc Thiên Tứ, arose to become the economic centre of the Gulf of Siam. After the fall of Ayutthaya, two Ayutthayan princes: Prince Chao Sisang and Prince Chao Chui, took refuge at Oudong the royal city of Cambodia and Hà Tiên, respectively. The Qing Chinese court at Beijing refused to recognize King Taksin as the ruler of Siam in Chinese tributary system because Mạc Thiên Tứ had told Beijing that the remaining descendants of the Ayutthayan dynasty were with him in Hà Tiên. In 1769, King Taksin urged the pro-Vietnamese King Ang Ton of Cambodia to send tributes to Siam. Ang Ton refused and Taksin sent armies to invade Cambodia in 1769 but did not meet with success.
In 1771, Taksin resumed his campaigns to invade Cambodia and Hà Tiên in order to find the Ayutthayan princes and to put the pro-Siamese Ang Non on the Cambodian throne. King Taksin ordered Phraya Yommaraj Thongduang (later King Rama I) to bring the army of 10,000 men to invade Cambodia by land, while King Taksin himself with Phraya Phiphit Chen Lian (陳聯, called Trần Liên in Vietnamese sources) as the admiral invaded Hà Tiên with the fleet of 15,000 men. Hà Tiên fell to Siamese invaders in November 1771. Phraya Yommaraj was also able to seize control of Oudong and Cambodia. Both Mạc Thiên Tứ and the Cambodian king Ang Ton fled to Cochinchina under the protection from the Nguyen Lord. Taksin appointed Chen Lian as the new governor of Hà Tiên with the title of Phraya Rachasetthi. The Siamese armies continued in search for Mạc Thiên Tứ and Ang Ton but were defeated by Vietnamese forces at Châu Đốc. Taksin put Ang Non in power in Cambodia with himself returning to Thonburi in December 1771, leaving Chen Lian in Hà Tiên and Phraya Yommaraj to be in charge in Cambodia.
Prince Chui was captured and brought to be executed at Thonburi, while Prince Sisang died in 1772. The Nguyen Lord Nguyễn Phúc Thuần organized the Vietnamese counter-offensives in order to restore Mạc Thiên Tứ and Ang Ton to their former positions. Chen Lian, the Siam-appointed governor of Hà Tiên, was defeated and left Hà Tiên for three days until he managed to raise a fleet to retake the city. The Vietnamese commander Nguyễn Cửu Đàm led the armies to seize control of Phnom Penh and Cambodia in July 1772, prompting Ang Non to move to Kampot. However, this Siamese-Vietnamese War coincided with the uprising of the Tây Sơn, which began in 1771, against the Nguyen Lord's regime. Instability at home made the Nguyen Lord order Mạc Thiên Tứ to make peace with Siam in 1773. Taksin then realized that the Siamese control over Cambodia and Hà Tiên was untenable. He ordered the withdrawal of Siamese troops from Cambodia and Hà Tiên in 1773 but not before 10,000 Cambodians were taken as captives to Siam.
Ang Ton resumed his rule in Cambodia. With the Vietnamese support dwindling due to the Tây Sơn uprising, however, Ang Ton decided to reconcile with his rival Ang Non and with Siam. Ang Ton abdicated in 1775 in favor of Ang Non, who became the new pro-Siamese King of Cambodia. With the Ayutthayan princes gone, the Qing court had improved attitudes towards Taksin.The Qing finally recognized Taksin as Wang (王) or King or the ruler of Siam in 1777 in the Chinese tributary system.
Conquest of Lanna
After the Burmese conquest of Lanna (modern Northern Thailand) in 1763, Lanna including Chiang Mai returned to the Burmese rule. Thado Mindin the Burmese governor of Chiang Mai oppressed the local Lanna nobles. King Taksin marched against the Burmese-held Chiang Mai in 1771 but failed to take the city. In Chiang Mai, Thado Mindin faced opposition from Phaya Chaban Boonma, the native Lanna noble who led the resistance against Burmese domination.
In 1772, King Hsinbyushin of the Burmese Konbaung dynasty realized that Siam had recovered and arose powerful under Thonburi regime. Hsinbyushin initiated a new campaign against Siam. He ordered troops to be gathered in Burmese Chiang Mai and the Mon town of Martaban in order to invade Siam from both the north and the west in two directions: a similar approach to the invasion of 1765-1767. In 1774, Binnya Sein, a nephew of Binnya Dala the last king of Hanthawaddy, led a failed Mon rebellion against Burma, resulting in the mass exodus of thousands of Mon people into Siam. Hsinbyushin appointed Maha Thiha Thura, the renowned general from the Sino-Burmese War, to be the supreme commander of the new campaigns and assigned Nemyo Thihapate, the Burmese general who had previously conquered Ayutthaya in 1767, to be in charge of Burmese forces in Lanna.
The Burmese forces from Chiang Mai attacked the Northern Siamese border towns of Sawankhalok in 1771 and Phichai in 1772-1773. Taksin was then resolved to extinguish Burmese threat from the north once and for all by conducting an expedition to seize the Burmese-held Chiang Mai in December 1774. This expedition to the north coincided with the Mon refugee situation. Phaya Chaban of Chiang Mai, upon learning of the Siamese invasion, joined with Kawila of Lampang to overthrow the Burmese. Phaya Chaban, under the guise of navigation, ran to submit to Taksin. King Taksin marched to Tak where he received the Mon refugees. Taksin ordered Chaophraya Chakri to lead the vanguard to Lampang, where Kawila had earlier insurrected against the Burmese. Kawila led the way for the Siamese armies to Chiang Mai. The brothers Chaophraya Chakri and Surasi combined forces to successfully seize Chiang Mai in January 1775. Burmese leaders Thado Mindin and Nemyo Thihapate retreated to Chiang Saen where they reestablished Burmese administrative headquarter. This began the transfer of Lanna from Burmese rule to Siamese domination after 200 years of Lanna being under Burmese suzerainty, even though northern parts of Lanna including Chiang Saen would remain under Burmese rule for another thirty years until 1804.
Phaya Chaban was rewarded with the governorship of Chiang Mai whereas Kawila was made the governor of Lampang. In 1777, the Burmese attacked Chiang Mai in their bid to reclaim Lanna. Phaya Chaban decided to evacuate Chiang Mai in the face of Burmese invasion due to numerical inferiority of his forces. Chiang Mai was then abandoned and ceased to exist as a functional city for twenty years until it was restored in 1797. Lampang under Kawila stood as the main frontline citadel against subsequent Burmese incursions.
Burmese invasions
Plan of King Hsinbyushin to invade Siam from two directions was foiled by the Mon Rebellion and the Siamese capture of Chiang Mai. Maha Thiha Thura, who had taken commanding position in Martaban, sent his vanguard force under Satpagyon Bo to invade Western Siam through the Three Pagodas Pass in February 1775. Taksin was unprepared as most of his troops were in the north defending Chiang Mai. He recalled the northern Siamese troops down south to defend the west. Satpagyon Bo took Kanchanaburi and continued to Ratchaburi, where he encamped at Bangkaeo (modern Tambon Nangkaeo, Photharam district), hence the name Bangkaeo Campaign. King Taksin sent preliminary forces under his son and his nephew to deal with the Burmese at Ratchaburi. The princes led the Siamese forces to completely encircle Satpagyon Bo at Bangkaeo in order to starve the Burmese into surrender. Northern Siamese troops arrived in the battlefield of Bangkaeo, bringing the total number of Siamese to 20,000 men, greatly outnumbering the Burmese. After 47 days of being encircled, Satpagyon Bo capitulated in March 1775. The Siamese took about 2,000 Burmese captives from this battle.