Conflict between the Burmese Empire and the Thai kingdom of Ayutthaya
The Burmese–Siamese War of 1765–1767, also known as the war of the second fall of Ayutthaya () was the second military conflict between Burma under the Konbaung dynasty and Ayutthaya Kingdom under the Siamese Ban Phlu Luang dynasty that lasted from 1765 until 1767, and the war that ended the 417-year-old Ayutthaya Kingdom.
Burma under the new Konbaung dynasty emerged powerful in mid-eighteenth century. King Alaungpaya the dynastic founder led his Burmese forces of 40,000 men, with his son Prince of Myedu as vanguard commander, invaded Siam in late 1759 to early 1760. The Burmese reached and attacked Ayutthaya in April 1760 but the arrival of rainy season and sudden illness of Alaungpaya prompted the Burmese to retreat. Traditional Siamese strategy of passive stand in Ayutthaya citadel against Burmese besiegers worked for one last time, postponing the eventual fall of Ayutthaya for seven years. Alaungpaya died on May 1760 on his way from Siam back to Burma. Burmese invasion of Siam in 1760, in which the Burmese, particularly Prince Myedu, had an opportunity to learn about Siamese geography, strategy and tactics and to reflect about their own flaws in the campaign, served as the foundation of the next Burmese invasion in 1765–1767. Prince Myedu ascended the Burmese throne as King Hsinbyushin in late 1763. Hsinbyushin inherited military energy and prowess from his father Alaungpaya and was determined to accomplish the unfinished mission of conquering Ayutthaya unattained by his father.
Burma sent forces to successfully conquer Lanna Chiang Mai in 1762–1763. In 1764, new Burmese king Hsinbyushin sent Ne Myo Thihapate with Burmese forces of 20,000 men to subjugate petty rebellions in Lanna and to proceed to invade Ayutthaya. Hsinbyushin also sent another 20,000 men under Maha Nawrahta to attack Siam from Tavoy in another direction, inflicting two-pronged pincer attack onto Ayutthaya. Siam, centered on the royal capital of Ayutthaya, was relatively defenseless against the militaristic Burmese. Due to long absence of external threats, Siamese defense system had been largely in disuse since the late seventeenth century. Chronic manpower shortage also crippled Siamese defense. Nemyo Thihapate conquered Lao kingdoms of Luang Prabang and Vientiane in March 1765. With the Burmese conquests of Lanna and Laos, the Burmese took control and outflanked Siam's northern frontiers and also had access to vast manpower and other resources.
In early 1765, Maha Nawrahta, from his base at Tavoy, sent his vanguard forces to invade and conquer Western Siamese provincial towns. Nemyo Thihapate, with his Burmese-Lanna contingents, descended onto Northern Siam in August 1765. Ayutthaya adopted hyper-centralized defensive strategy by calling provincial forces to defend Ayutthaya, focusing on protecting the royal city itself, leaving peripheral provincial cities less defended at the mercy of Burmese invaders. Within the conquered Siamese provincial cities, Burmese commanders recruited local Siamese men to join their ranks. In October 1765, Maha Nawrahta, with his main Tavoy column, invaded Siamese Chao Phraya heartland. William Powney the British merchant, at the request of Ayutthayan court, engaged with Maha Nawrahta's Burmese forces in the Battle of Nonthaburi in December 1765 but the Burmese prevailed.
Maha Nawrahta, with his Tavoy column coming from the west and Nemyo Thihapate with his Lanna column coming from the north, converged on Ayutthaya in January to February 1766, setting foot on the outskirts of Ayutthaya. Maha Nawrahta took position at Siguk to the west of Ayutthaya, while Nemyo Thihapate encamped at Paknam Prasop to the north of Ayutthaya. Siamese king Ekkathat sent Siamese defense forces in attempts to dislodge Burmese invaders from those places but failed. Siamese resistance group known as Bang Rachan emerged in February 1766 and ended in June, though not significantly impacting the course of the war but showcasing a side story of Siamese patriotic deeds that was later emphasized and celebrated by modern nationalistic Thai historiography of later centuries.
For fourteen months, from February 1766 to April 1767, Ayutthaya endured the Burmese siege. Ayutthaya invoked the traditional strategy of passive stand inside of the Ayutthaya citadel, relying on two main defenses; the supposedly impregnable city wall fortified by French architects during the reign of King Narai and the arrival of wet rainy season. The Ayutthayans initially fared well as the foods and provisions were plentiful and the Siamese simply waited for the Burmese to leave but the Burmese besiegers did not intend to retreat. Learning from the previous invasion of 1760, King Hsinbyushin innovated and devised new strategy to overcome Siamese defenses. The Burmese would not leave during rainy season but would stand their grounds and endured wet swamps in order to pressure Ayutthaya into surrender. Burmese besiegers closed in and approached Ayutthaya in September 1766, with Nemyo Thihapate coming closer at Phosamton and Maha Nawrahta at Wat Phukhaothong temple. By late 1766, the situation became dire and desperate for Ayutthayan inhabitants as they ran out of food and resources, many simply surrendering themselves to the Burmese.
Desperate, a Siamese military man of Teochew Chinese descent known as Phraya Tak gathered his Chinese–Siamese forces to break through the Burmese line to Eastern Siam in early January 1767, seeking for new position. Developing simultaneously was the Sino-Burmese War. Conflicts between Burma and Qing China over the frontier Shan States led to Yang Yingju the viceroy of Yungui sending Chinese Green Banner forces to directly invade Burma in October 1766. This prompted Burmese king Hsinbyushin, in January 1767, to command the Burmese besiegers in Ayutthaya to finish up the conquest of Ayutthaya in order to divert their forces to the Chinese front. Maha Nawrahta then escalated the siege by constructing twenty-seven forts surrounding Ayutthaya. In February to March 1767, Ayutthaya sent out volunteer Chinese and Portuguese Catholic fighters as the last line of defense, who were also defeated. Maha Nawrahta died from illness in March 1767, leaving his colleague Nemyo Thihapate to assume commands over the whole Burmese besieging forces.
Nemyo Thihapate came up with a tactic to circumvent the Ayutthayan wall by digging underground tunnels into Ayutthaya. In early April 1767, the Burmese, through the tunnels, set fire to the roots of the wall, causing the northeastern portion of Ayutthayan wall to collapse, allowing the Burmese to eventually enter Ayutthaya. Ayutthaya, Siamese royal capital for four centuries, fell to the Burmese on 7 April 1767. What followed were violent scenes of the Burmese massacring of the inhabitants, burning of Siamese royal palaces, temples and vernacular structures and looting for treasures. Ekkathat, the last king of Ayutthaya, was either killed by a random gunshot or by starvation. 30,000 Siamese people, along with members of the fallen dynasty, craftsmen and cultural artifacts were all taken back to Burma. Nemyo Thihapate occupied the ruins of Ayutthaya for two months until his departure in June 1767, leaving only a small contingent under the Mon official Thugyi at Phosamton to oversee the short-lived Burmese occupation of Lower Central Siam, while the rest of the kingdom broke down into a number of competing regional regimes.
Burma diverted most of Ayutthaya occupation forces to the Chinese front, giving Siam a golden opportunity to resurge. Phraya Tak, the Siamese leader of Teochew Chinese heritage, who had earlier taken position in Eastern Siam, raised troops there to expel the Burmese and reconquered Ayutthaya-Thonburi area in November 1767. Ayutthaya was too ruinous and untenable to serve as Siam's capital so Phraya Tak, newly enthroned as King Taksin in December 1767, moved the Siamese royal seat to Thonburi south of Ayutthaya. Ayutthaya continued to exist as a second-class provincial towns, with its structural bricks dismantled for construction of Bangkok and its wealth looted by treasure hunters. After finishing the Chinese war in 1769, Hsinbyushin resumed the campaign to attack Siamese Thonburi kingdom in 1775–1776. However, Siam under the new regime was more resilient and competent at defense against Burmese invasions. Burmese invasion of Siam in 1785–1786 would be the last major large-scale Burmese invasion of Siam in history. Siam lost Tenaserim to Burma for perpetuity in 1765, becoming modern Tanintharyi region (Siam attempted to regain Tenasserim in 1792–1794 but failed.), in exchange for taking control of Lanna or modern Northern Thailand from Burma in 1775.
Background.
Rise of the Konbaung dynasty.
With the weakening of centuries-old Burmese Toungoo dynasty by mid-eighteenth century, the Mons in Lower Burma were able to break free and form their own kingdom. The Mons elected the monk Smim Htaw Buddhaketi to be their king of their Restored Hanthawaddy Kingdom in 1740. Smim Htaw, however, was deposed by a coup and replaced by his prime minister Binnya Dala in 1747 with Smim Htaw fleeing to Ayutthaya. Maha Damayaza Dipati, the last king of Toungoo dynasty, had authorities only in Upper Burma. Binnya Dala sent his brother Upayaza to lead Mon armies to conquer Upper Burma in 1751. Upayaza was able to seize Ava, the Burmese royal capital, in 1752, capturing Maha Damayaza Dipati to Pegu and ending the Toungoo dynasty.
When Ava was falling to the Mon invaders, a local village chief of Moksobo named U Aung Zeiya rallied Burmese patriots to rise against the Mons. Aung Zeiya was enthroned as King Alaungpaya in 1752, founding the new Burmese Konbaung dynasty. Siam took hostile attitudes towards the Mon kingdom, leading to the Mons being preoccupied with possible Siamese threats from the east and allowing Alaungpaya to gather his Burmese forces and consolidate in Upper Burma. Alaungpaya's son Thado Minsaw (later Hsinbyushin) retook Ava from the Mons in 1754. Alaungpaya mobilized his Burmese forces to invade Lower Burma in the same year, capturing Prome in 1755 and attacking Syriam, where British and French traders had been residing, in 1756. Alaungpaya took Syriam in 1756 and killed French officials there for he was informed that the French had supported the Mons. Alaungpaya also seized two French ships containing field guns, thousands of flintlock muskets and other ammunitions – a great haul to Burmese armory. Alaungpaya then laid siege on Pegu, the Mon royal seat. The panicked Mon King Binnya Dala executed the former Burmese king Maha Damayaza Dipati, inadvertently giving Alaungpaya full legitimacy as the savior of Burmese nation. Alaungpaya seized Pegu in May 1757, thus unifying Upper and Lower Burma under him. Pegu was destroyed and the political administrative center of Lower Burma shifted from Pegu to Rangoon.
Internal developments of Ayutthaya.
Burmese armies had not reached the outskirts of Ayutthaya since 1586 and, after King Naresuan's victory over the Battle of Nong Sarai in 1593, there had not been serious threatening Burmese invasions since then. In the aftermath of Siamese Revolution of 1688, Phetracha ascended the throne and founded his Ban Phlu Luang dynasty of the Late Ayutthaya Period, which was known for internal conflicts, including those in 1689, 1699, 1703 and 1733, owing to increasing powers of royal princes and nobility. Phetracha faced undaunting rebellions at regional centers of Nakhon Ratchasima (Khorat) and Nakhon Si Thammarat (Ligor) in 1699–1700, which took great efforts to quell. Siamese court of Late Ayutthaya, therefore, sought to decrease the powers of provincial governors. However, this reform became a failure and Ayutthayan court eventually lost effective control over its periphery.
In pre-modern Siam, the military relied on conscripted levies as the backbone rather than professionally-trained personnel. In Late Ayutthaya Period, in early eighteenth century, Siam's rice export to Qing China grew. Siam became a prominent rice exporter into China through Teochew Chinese merchants. Siamese "Phrai" commonners of Central Siam, who cleared more lands and cultivated more rice for exports, became enriched through this economic prosperity and they became less willing to participate in military conscription and corvée levies. The "Phrai" evaded conscription through capitation taxes or commodity taxes and outright absence in order to partake in other more-profitable commercial activities. This led to overall decline of effective manpower control of Siamese Ayutthayan royal court over its own subjects. When Dowager Queen Yothathep died in 1735, there was not enough men to parade her funeral so King Borommakot had to relegate his own palace guards to join the procession. In 1742, the royal court managed to round up ten thousands of conscription evaders. Suppression of local governors means that they were less-armed and unable to provide frontline defenses against external invaders. Chronic manpower shortage undermined Siam's defense system. Government structure of Late Ayutthaya served to ensure internal stability and to prevent insurrections rather than to defend against invasions. Internal rebellions were more