The Ava–Hanthawaddy War (1408–1418) () was the third major conflict of the Forty Years' War, fought between Ava and Hanthawaddy Pegu, both located in present-day Myanmar. The decade-long war escalated into a multi-front, multi-sided conflict that also involved China and Siam. Hanthawaddy and China successfully checked Ava's expansion drive.
The casus belli stemmed from Ava's expansion under King Minkhaung I, who after the Ava–Hanthawaddy War (1401–1403) annexed the nearer Shan states and Launggyet Arakan (1404–1406). While the Ming court warned Ava to end its "aggression", King Razadarit of Hanthawaddy feared he was next, and seized Arakan in March 1408. A furious Minkhaung hastily invaded the southern kingdom but his forces were decimated during the punishing rainy season. His subsequent 1409–1410 invasion also failed, leading a dejected Minkhaung to cede command to his eldest son, Crown Prince Minye Kyawswa.
Minye Kyawswa brought a new, flexible strategy, focusing on the Irrawaddy delta rather than the difficult Sittaung front. When his inaugural delta invasion stalled in late 1410, he swiftly redirected his forces to Arakan, capturing the region in March 1411. However, he was soon forced to leave the front due to the imminent Chinese threat—the Yongle Emperor had authorized military action against Ava—which allowed Hanthawaddy to retake Arakan by early 1412.
Both kingdoms were soon forced to fight on multiple fronts. In April 1412, the Chinese vassal Hsenwi invaded Ava's northeast, advancing to Wetwin—just 80 kilometers from Ava (Inwa). Minye Kyawswa successfully repulsed the invasion, besieged Hsenwi throughout the rainy season, and defeated a 20,000-strong Chinese relief army in October. In November, Razadarit opened Ava's southern front to relieve pressure on Hsenwi by laying siege to Prome (Pyay). One month into the siege, Siamese forces opportunistically invaded Hanthawaddy's southernmost districts, forcing Razadarit to lead the majority of his forces to drive them out. This allowed Ava forces to launch a counter-invasion, and occupy the delta by May 1413.
However, Ava's momentum was again stalled as China and its vassals continued to attack Ava's northern districts throughout 1413–1415. In 1413, Minkhaung had to recall Minye Kyawswa to chase Maw (Mong Mao) forces to the Chinese border. In his final invasion, Minye Kyawswa recaptured the entire delta in 1414, but could not breach the formidable defensive line of Dala, Dagon and Syriam, en route to Pegu (Bago). Minkhaung refused to send reinforcements as the Chinese threat remained. The war's climax came during a Hanthawaddy counterattack on 13 March 1415 when Minye Kyawswa fell in action outside Dala.
The war lost its intensity afterwards. China stopped its invasions after 1415. A grief-stricken Minkhaung stopped all military action until Razadarit sent a minor probe in 1416. Minkhaung ordered a final retaliatory campaign in 1417–1418, after which he declared the two kingdoms "even." This resulted in an unofficial peace that held until both rival kings died in 1421. Hanthawaddy had succeeded in maintaining its independence, while Ava had lost Arakan but secured its nearer Shan states. The peace broke down in 1422 when Minkhaung's successor, King Thihathu, intervened in a Pegu succession crisis, starting the Ava–Hanthawaddy War (1422–1423).
Background This was the third war between Ava and Hanthawaddy Pegu. In the first two wars, each kingdom attempted to exploit the other's succession crisis. In the first war (1385–1391), King Swa Saw Ke of Ava unsuccessfully tried to replace the new king of Hanthawaddy, Razadarit.Harvey 1925: 82–85Htin Aung 1967: 88 Conversely, Razadarit attempted to gain the submission of Ava's new king Minkhaung I in the second war (1401–1403).Aung-Thwin 2017: 254–255Fernquest Spring 2006: 10–11
Minkhaung emerged stronger after the second war. Not only was he able to negotiate a favorable peace treaty with RazadaritHmannan Vol. 1 2003: 470Harvey 1925: 90 but he had also finally gained the support of his vassals. Minkhaung immediately began using his newfound power. Ava went on to take over its neighboring Shan states to the east and the north: Onbaung (1404/05), Yatsauk and Nyaungshwe (1405/06),Yazawin Thit Vol. 1 2012: 224–225 and Bhamo and Mohnyin (1406).Fernquest Autumn 2006: 51
Ava's acquisition spree alarmed its neighbors. In August 1406, the Ming court, which considered the Shan states its tributaries, dispatched an embassy to Ava (Inwa), ordering the kingdom to end its "aggression" in the border states. At Pegu, the concern was far greater. Razadarit had been wary about Ava's potential threat to Pegu since the end of the second war.Hmannan Vol. 1 2003: 467 According to the Razadarit Ayedawbon chronicle, October 1406, the king received intelligence that his court deemed credible: Ava planned to invade Launggyet Arakan next, followed by Pegu.Pan Hla 2005: 237–239
Pegu's suspicions were seemingly confirmed shortly after. In November 1406, Ava forces led by Minkhaung's eldest son Prince Minye Kyawswa invaded Arakan on the western littoral.Sandamala Linkara Vol. 2 1999: 9 In response, Razadarit and his army rushed to Bassein (Pathein) to closely monitor the events across the Arakan border. Although Ava forces never crossed the Arakan–Hanthawaddy border, the Pegu court was convinced that Pegu was indeed next.
Prelude to war
Razadarit immediately removed the veneer of friendly relations with Ava. He readily gave shelter to King Min Saw Mon (and/or Prince Min Khayi) of Launggyet Arakan. A few months later, he welcomed Minkhaung's younger brother Prince Theiddat who had defected for being passed over as crown prince.Yazawin Thit Vol. 1 2012: 227Hmannan Vol. 1 2003: 473–474Aung-Thwin 2017: 75 More significantly, he stopped sending the annual shipment of elephants and the annual customs revenues of the port of Bassein as required per the 1403 Treaty of Kawliya. With the treaty now nullified, Pegu prepared for an Ava invasion after the rainy season.
However, the anticipated invasion never came. When they learned that Ava was busy suppressing a serious rebellion in Bhamo, the Hanthawaddy command deliberated their next steps. Over the next few months, they concluded that they must act while Ava was preoccupied in the north. They chose to capture Arakan first, which they believed would be easier than confronting Ava's formidable southern defenses.Yazawin Thit Vol. 1 2012: 228Harvey 1925: 91 Razadarit did not make the decision lightly, as he was about to start a war against a far more populous kingdom. In January 1408, the king prayed solemnly at the main pagoda of Pegu (presumably the Shwemawdaw) before finally authorizing the Arakan campaign.
Hanthawaddy conquest of Arakan (1408) Preparations
Pegu's general plan was to conquer Arakan swiftly by leveraging the popularity of Min Saw Mon. The Hanthawaddy command believed the dethroned king's presence would entice the local populace to join their side. Their battle plan called for capturing Sandoway (Thandwe) first, enlisting more men from southern Arakan, and finally attacking Launggyet in the north.Pan Hla 2005: 240 An expeditionary force was organized, consisting of two divisions (totaling 4000 to 5000 troops), commanded by Smin Paik-Nye and Smin Maw-Khwin. By late February, the expeditionary force and the royal army commanded by Razadarit himself were all massed in Bassein.
Meanwhile, Ava was oblivious to the impending threat. Its main forces were still in Bhamo,Pan Hla 2005: 241 and had not reinforced its nominal garrisons in Launggyet and Sandoway.
Campaign
The invasion began early March 1408. The Hanthawaddy expeditionary force took Sandoway unopposed. The small Ava garrison there had fled to Launggyet just prior. The allied forces—Min Saw Mon now commanded a force of his own—then marched to the capital. At Launggyet, the Ava-installed king Anawrahta tried to resist from behind the city walls. Three vanguard forces–led by Smin Sam Lek, Smin Lauk Ni-Ye and Min Saw Mon—quickly breached the defenses, and defeated the Ava garrison inside. Anawrahta, his queen Saw Pyei Chantha, and 300 household guards, were taken prisoner.
Aftermath After the campaign, Min Saw Mon was restored to the Launggyet throne. Razadarit immediately recalled most of the expedition force. The captured king and queen of Arakan were also brought back. Razadarit had Anawrahta executed, and took his queen, Saw Pyei Chantha, the 16-year-old daughter of Minkhaung, as one of his own.Aung-Thwin 2017: 78
The provocations worked. At Ava, a furious Minkhaung ordered an immediate invasion of Hanthawaddy. His court was aghast. With the rainy season only two months away, the ministers tried to persuade Minkhaung to delay the campaign. But the king insisted on an immediate invasion.Phayre 1967: 72
First Ava invasion of Hanthawaddy (1408)
Ava preparations
The Ava court hastily drew up a plan. Their first priority was to make peace with China. Minkhaung, who had not responded to the 1406 Chinese mission, finally sent an embassy to Beijing. Its purpose was to reassure the Yongle Emperor about Ava's intentions on their borderlands. The embassy, received on 28 May 1408, succeeded in lowering the tensions with China—at least temporarily. Ava also dispatched an embassy to Chiang Mai to persuade the king of Lan Na (present-day northern Thailand) to open a front from Pegu's east. However, the embassy veered into Hanthawaddy territory en route, and was arrested. Razadarit released the embassy back to Ava, with Minkhaung's letter to the king of Lan Na unsealed.Maha Yazawin Vol. 1 2006: 332–333
Ava would thus have to fight Pegu alone. By April, a vanguard army (22,000 troops, 2000 cavalry, 80 elephants), and a smaller army (4000 troops, 200 cavalry and 20 elephants) commanded by Minkhaung himself had been organized.Hmannan Vol. 1 2003: 476–477 To beat the rains, the Ava command decided to send both armies along the Sittaung river. This was the shortest path to Pegu but it was also much harder to supply. Their plan was to ship supplies via the Irrawaddy river to Prome (Pyay), and then transport them by land (over 200 km by modern roads) through the jungles of the Pegu Yoma range to the front.Maha Yazawin Vol. 1 2006: 334
Pegu battle plan
Hanthawaddy defenses were ready on both the Irrawaddy delta and Sittaung fronts. They expected invasion forces of around 15,000 infantry, 600 cavalry and 60 elephants. The plan called for ambushing the more numerous Ava troops along the invasion routes, and defending from inside fortified towns.Pan Hla 2005: 242–243 Dein Mani-Yut would lead the defense of the delta while Razadarit himself would lead the defense of the Sittaung front with his main army (8000 troops, 300 cavalry, 20 elephants), operating out of Fort Thagyin (present-day Shwegyin), about 100 km northeast of Pegu.Maha Yazawin Vol. 1 2006: 334–335Yazawin Thit Vol. 1 2012: 229Hmannan Vol. 1 2003: 477 Smin Ye-Thin-Yan guarded the capital.Pan Hla 2005: 243, 263
Invasion
Initial campaign In April 1408, the Ava vanguard regiments began the invasion at the Sittaung front. A 500-strong vanguard regiment led by Lagun Ein promptly ambushed the enemy, inflicting high casualties before being driven back by the more numerous Ava troops.Pan Hla 2005: 243 Spooked by the high losses, Minkhaung paused the invasion for another six days until more troops could arrive.Pan Hla 2005: 245