The Burmese–Siamese War of 1849–1855 or Siamese Invasions of Kengtung or Kengtung Wars were military expeditions of the Siamese Rattanakosin Kingdom against the Tai Khün State of Kengtung, which had been under Burmese suzerainty under the Konbaung dynasty. The dynastic struggles in Tai Lue State of Chiang Hung or Sipsongpanna prompted Siam, in cooperation with the Kingdom of Lanna (Northern Thailand), to invade Kengtung in order to gain access to Chiang Hung. In the First Invasion in 1850, the Siamese court had ordered the Lanna Lord of Chiang Mai to organize the offensives against Kengtung. Lanna troops failed to conquer Kengtung. Two other expeditions occurred in 1852 and 1853 as Bangkok commanded its troops to directly participate in the invasions. Both expeditions also failed because of internal issues and geographical unfamiliarity. The State of Kengtung under the leadership of Saopha Maha Khanan (Maha Hkanan), with limited assistance from mainland Burma who had been embroiling in the Second Anglo-Burmese War, managed to resist Siamese-Lanna invasions three times.
Prelude to conflict History of Kengtung Kengtung was founded as a city by King Mangrai of Ngoenyang in 1253 and later became part of the Tai Yuan Kingdom of Lanna, which encompasses modern Northern Thailand. In 1350, King Phayu of Lanna sent his son to rule Kengtung. His dynasty would continue to rule Kengtung for another six hundred years until 1959. Kengtung later freed itself from Lanna and developed its own ethno-cultural entity as Tai Khun people. In 1558, the Kingdom of Lanna fell to King Bayinnaung of the Burmese Toungoo dynasty. The ruler of Kengtung submitted to the Burmese rule. The Burmese court appointed the local ruler of Kengtung, who had descended from the Mangrai clan, as Saopha under Burmese domination.
In the late eighteenth century to early nineteenth century, Lanna had freed itself from Burmese domination and came under Siamese rule. The Lanna Lords adopted the policy of “Picking vegetables into baskets, putting men in towns” to wage wars to seek manpower. The Northern Tai states of Kengtung and Chiang Hung, known collectively in Thai sources as "Lü-Khün", were the main victims of forced resettlement policy to repopulate the Lanna region, which had been ravaged by prolonged warfare. In 1802, Phraya Kawila of Chiang Mai sent his younger brother Phraya Uparaj Thammalangka to capture Mong Hsat and Kengtung, forcibly deporting thousands of Khun people from Kengtung and Mong Hsat to resettle in Chiang Mai. Sao Kawng Tai, the then saopha of Kengtung, fled and later submit to Chiang Mai authority in 1804. Maha Khanan, younger brother of Sao Kawng Tai, established himself at Mong Yawng as an independent ruler. Maha Khanan endured many invasions from Burma, who sought to reclaim Kengtung. After the protracted guerilla warfare, Maha Khanan decided to accept the Burmese suzerainty in 1813 and Kengtung once again came under Burmese rule.
Dynastic conflicts in Chiang Hung Khun Chueang or Phaya Chueang founded the city of Chiang Hung of Chiang Rung (modern Jinghong) and the Tai Lue confederacy of Sipsongpanna (Twelve “pannas”, corresponding to modern Xishuangbanna Dai Autonomous Prefecture) in around 1180. Sipsongpanna was incorporated into the Lanna Kingdom by King Mangrai. The Mongols of Yuan dynasty invaded Sipsongpanna and Chiang Hung surrendered to the Mongols in 1296. The subsequent Ming and Qing appointed the Tai Lue rulers of Chiang Hung as native governor or Tusi with the title of "Chēlǐ Pacification Commissioner" ( pinyin: Chēlǐ xuānwèishǐ). The city of Chiang Hung was known as Chēlǐ (). The Chinese sent a seal to confirm the rulers of Sipsongpanna. In 1563, King Bayinnaung of Burma captured Chiang Hung. The Burmese and the Chinese agreed on the joint domination over Sipsongpanna, whose ruler was enthroned in a ceremony in which both Burmese and Chinese representatives jointly presided. "China was the father, Burma was the mother." The rulers of Chiang Hung then had to seek confirmation from both China and Burma.
In 1802, Prince Mahavong the ruler of Chiang Hung died. His two-year-son Prince Tsau Mahanavi was confirmed to succeed his father under the regency of Prince Tsau Mahavang, who had been Mahanavi's uncle. When Mahanavi reached maturity in 1817, he personally assumed the governorship. King Bodawpaya summoned Prince Mahanavi of Chiang Hung to Amarapura to confirm his submission. Mahanavi did not go and sent his uncle Mahavang to go to Amarapura instead. King Bodawpaya was angered at Mahanavi's defiance and enfeoffed Mahavang to replace his nephew as the ruler of Chiang Hung. The civil war between Tsau Mahanavi and Tsau Mahavang in Sipsongpanna ensued for decades. In 1834, the Qing, who supported Mahavang, managed to chase Mahanavi off Chiang Hung. Mahanavi fled and died.
In 1836, Prince Mahavang of Chiang Hung died. His son Tsau Suvanna was made to succeed him and Mahavang's another younger son Amaravuth was made Uparaj or heir. However, his nemesis Mahanavi had left a son named Nokham. Prince Nokham gained support from the Burmese court under King Tharrawaddy Min to support him against Suvanna. King Tharawaddy Min of Burma sent the Burmese Sitke general to lead a Burmese army of 3,000 men to invade Chiang Hung and to put Nokham on the Tai Lue throne in 1836. Lady Pinkaew, wife of Mahavang and mother of Suvanna and Amaravuth, bribed the Burmese Sitke to retreat. The Sitke general captured Chiang Hung and made Nokham the ruler of Chiang Hung. Seven days after, Lord Mahachai of Mengpeng who was a supporter of Suvanna led troops to recapture Chiang Hung. The Burmese general then feigned retreat along with Nokham as he was bribed by Lady Pinkaew. Mahachai of Mengpeng restored Suvanna to the throne of Chiang Hung.
Prince Nokham did not give up. He persuaded King Tharrawaddy to send another army of 10,000 men to capture Chiang Hung again in his favor in 1838. Four years later in 1842, the Qing authorities in Yunnan encouraged Mahachai of Mengpeng to successfully retake Chiang Hung and restore Suvanna to the throne for the second time. This time Suvanna managed to secure confirmation from the Burmese Ava court. Everything seemed peaceful until Nokham took Chiang Hung again in 1849. Prince Suvanna fled to Ava. His brother Amaravuth and his mother Pinkaew took refuge in Luang Phrabang, which had been under Siamese suzerainty. Mahachai fled to Vieng Phouka. King Sukkhasoem of Luang Phrabang then sent the Tai Lue royals; Amaravuth, Lady Pinkaew and Mahachai to Bangkok.
First Siamese Invasion of Kengtung (1850)
King Rama III sent troops to assist Tsau Suvanna of Chiang Hung against Nokham to uphold the chakravatin ideology of universal ruler, which signified the honor and power of the Siamese kingdom in the region. However, in order to take Chiang Hung, Siam had to occupy Kengtung first as its provided line of communications. The Bangkok court did not directly involve by sending its own troops to realize the goal. Instead, the Lanna lords of Chiang Mai and Lamphun were assigned for the mission. King Rama III ordered Phraya Mahavong the Ruler of Chiang Mai to arrange Lanna armies into Kengtung. Phraya Mahavong of Chiang Mai then mustered the Lanna army composing of 5,000 men from Chiang Mai, 1,500 men from Lamphun and 1,000 men from Lampang. The regiments were arranged in the following orders to invade Kengtung;
Army of Phraya Uparaj Phimphisan and Phraya Burirattana (son of King Kawila) would march through Chiang Rai to reach Kengtung. Army of Phraya Raxabut and Noi Mahaphrom (son of Phraya Mahavong) would march through Mong Hsat.
The two armies left Chiang Mai for Kengtung in February 1850. The army of Phraya Raxabut and Noi Mahaphrom successfully captured Mong Hsat, where they continued to Mong Gouk and captured several satellite towns of Kengtung. They eventually laid siege on Kengtung in March 1850.
When the army of Phraya Uparaj Phimphisan had reached Chiang Rai, he ordered Phraya Burirattana to attack and capture Mong Hpayak. Uparaj Phimphisan himself negotiated a peaceful surrender from Mong Yawng and stationed there. Phraya Raxabut and Noi Mahaphrom led assaults on the walls of Kengtung but saopha Maha Khanan of Kengtung successfully repelled the invaders. The Lanna side suffered from manpower shortage as the army of Uparaj Phimphisan did not coalesce with them at Kengtung as planned. Noi Mahaphrom sent his man to urge Uparaj Phimphisan at Mong Yawng to reinforce them at Kengtung but Uparaj Phimphisan did not respond. After being depleted of gunpowder with Kengtung persisted, Phraya Raxabut and Noi Mahaphrom decided to retreat the Lanna troops from Kengtung.
The First Invasion of Kengtung by Lanna in 1850 did not succeed. Maha Khanan managed to strongly repel the Lanna invaders. The discord among the Lanna lords prevented them from successfully taking Kengtung in the same manner with what they had accomplished before in 1802. Phraya Mahavong of Chiang Mai issued a letter of apology to King Rama III at Bangkok, beseeching him for Bangkokian assisting troops and additional cooperation from Nan. However, the king had been ill. King Rama III died in April 1851.
Second Siamese Invasion of Kengtung (1852–1854)
The expedition against Kengtung in 1850 did not succeed and Siam failed to support Suvanna and to gain control of Kengtung and Chiang Hung. The Qing raised an army to defeat Nokham at Chiang Hung and Nokham was killed. The Qing managed to restore Suvanna to the throne of Sipsongpanna. Amaravuth, Lady Pinkaew and Mahachai, the Tai Lue royals, who had been staying in Bangkok for about three years, took the permission of King Mongkut to return to the north. Amaravuth and Lady Pinkaew returned to Luang Phrabang, while Mahachai returned to Nan.
In 1852, Suvanna of Chiang Hung dispatched a mission, along with ceremonial golden and silver trees, to Bangkok to request the return of his family members to Chiang Hung. King Mongkut granted the permission for the Tai Lue royals to return to their homeland. However, the ministers at the court of Bangkok petitioned to King Mongkut to send another expedition into Chiang Hung. Like the previous occasion in 1850, Siam had to take Kengtung first before proceeding to Chiang Hung. Burma was then being embroiled in the Second Anglo-Burmese War and should not be able to provided supports to Kengtung, which was a tributary state of Burma. King Mongkut then ordered the following armies, with total number of 10,000 men, to Kengtung. On this occasion Bangkok was involved directly by sending its troops in the campaigns;
Prince Vongsathirat Sanid, younger half-brother of King Mongkut, would lead an army through Phitsanulok and Nan to Kengtung. Chao Phraya Yommaraj Nuch would lead an army through Tak and Chiang Mai to Kengtung. He was to join by the Lanna forces under the leadership of Phraya Uparaj Phimphisan and Phraya Burirattana. The two armies planned to converge at Chiang Saen before proceeding to Mong Hpayak and then to Kengtung.
First Expedition (1852–1853) Chao Phraya Yommaraj Nuch left Bangkok with his army in October 1852. He proceeded through Kamphaengphet and Tak, drafting the conscripted militias along the way. Yommaraj Nuch reached Chiang Mai on December 19, 1852, where he recruited Lanna forces. Prince Vongsathirat Sanid left Bangkok November 13, 1852, with his army. He proceeded through Nakhon Sawan, Phitsanulok, reaching Nan in January 1853. He was reinforced and supplied by Chao Phraya Mongkol Vorayot the ruler of Nan. Yommaraj Nuch and his Lanna-Siamese army left Chiang Mai for Chiang Saen in February. Prince Vongsathirat Sanid eventually reached Chiang Saen on February 17. Chao Phraya Yommaraj Nuch followed to Chiang Saen three days later. The prince ordered Chao Phraya Yommaraj Nuch to be his vanguard, with the joint Bangkok-Chiang Mai army of total 5,042 men, who left first from Chiang Saen to Mong Hpayak on February 24.