The Ava–Hanthawaddy War (1430–1431) () was a military conflict fought between the northern Kingdom of Ava and the southern alliance consisting of the Kingdom of Hanthawaddy Pegu and the rebel state of Toungoo. This conflict was the fifth of the decades-long wars between Ava and Pegu, both located in present-day Myanmar. Ava was forced to cede its southernmost districts to Pegu in exchange for Pegu's withdrawal of support for Toungoo.
The war's origins stemmed from the prolonged civil war in Ava that began in 1426. Viewed as a usurper by many major vassals, Thado of Mohnyin, Ava's new king, faced multiple rebellions across the kingdom. In Ava's south, Governor Saw Lu Thinkhaya formed a southern alliance, backed by King Binnya Ran I of Hanthawaddy. While Thado was preoccupied by rebellions in central Ava, the alliance went on to seize Ava's southern districts: Tharrawaddy and Paungde by Hanthawaddy in 1427, and the five irrigated districts of Yamethin by Toungoo in 1428–1429.
The war formally began when the alliance laid siege to Prome, Ava's main southern fortress, in October 1430. Unwilling to wage a long southern campaign, Thado offered to negotiate directly with King Binnya Ran. After over three months of negotiations, both sides reached agreement in February 1431. Under the Treaty of Prome, Ava formally ceded Tharrawaddy and Paungde to Hanthawaddy while Pegu agreed to withdraw its support for Toungoo. Ran also married Princess Soe Min Wimala Dewi in a marriage of state, cementing the agreement.
The war established Hanthawaddy as the ascendant power in the immediate aftermath. Toungoo was isolated, becoming a Hanthawaddy protectorate in 1436. Ava remained politically fragmented throughout the 1430s, and did not regain Toungoo until 1441, and Tharrawaddy and Paungde until 1446.
Background Ava and Hanthawaddy Pegu fought their previous war between 1422 and 1423. The war, the fourth since 1385, concluded with an alliance between King Thihathu of Ava, and Crown Prince Binnya Ran of Hanthawaddy. As part of the agreement, Ran renounced his claim on Tharrawaddy, and Thihathu withdrew his forces from the Irrawaddy delta. To cement the alliance, Thihathu married Princess Shin Saw Pu, Ran's younger sister.Aung-Thwin 2017: 261–262Htin Aung 1967: 93Hmannan Vol. 2 2003: 57
After the war, Ran emerged as the strongest ruler in the fragmented southern kingdom. He seized the Hanthawaddy throne after his older half-brother and rival King Binnya Dhammaraza was assassinated in late 1424. Ran secured unity in the kingdom by granting his younger half-brother, Prince Binnya Kyan, considerable autonomy at Martaban. In exchange, Kyan agreed to share the region's lucrative commercial revenue with the crown. The arrangement succeeded, and Pegu was once again led by a strong leader.Aung-Thwin 2017: 262
Meanwhile, Ava spiraled towards political instability. King Thihathu neglected governing, preferring to spend time with Queen Shin Saw Pu and his concubines.Yazawin Thit Vol. 1 2012: 269 In 1425, his former favorite Queen Shin Bo-Me engineered two assassinations within a three-month period: first of Thihathu, and then of his eight-year-old successor Min Hla. Bo-Me then placed her lover Prince Min Nyo of Kale on the throne, making herself the chief consort.Yazawin Thit Vol. 1 2012: 270Hmannan Vol. 2 2003: 58Harvey 1925: 95–96
Unlike Binnya Ran at Pegu, Nyo was not accepted as a unifying figure. Many vassals considered his accession illegitimate. In May 1426, Governor Thado of Mohnyin, one of the key vassal rulers, drove out Nyo and Bo-Me following a three-month civil war. However, major vassals still regarded Thado as another usurper, and refused to submit.Aung-Thwin 2017: 82 In late 1426, Prince Minye Kyawhtin with the backing of a fellow vassal Le Than Bwa of Onbaung, raised a rebellion in central Ava, sparking a new round of revolts across the kingdom.Aung-Thwin 2017: 85Harvey 1925: 97
Prelude to war Toungoo–Pegu alliance (1426) In Ava's south, Saw Lu Thinkhaya emerged as the main opponent to Thado's regime. Thado had heavily courted him because Toungoo was strategically located in Ava's southeast bordering Hanthawaddy. Despite an offer of autonomy from Thado, Thinkhaya formally declared independence shortly after Minye Kyawhtin's revolt.Yazawin Thit Vol. 1 2012: 274Hmannan Vol. 2 2003: 64–65 Thinkhaya proceeded to form alliances with neighboring rulers, Thihapate III of Taungdwin, his younger brother Anawrahta of Paungde, and most importantly, King Binnya Ran I of Hanthawaddy.Sein Lwin Lay 2006: 28Hmannan Vol. 2 2003: 65, 71
In Pegu, Ran was eager to extend his influence into southern Ava. He readily agreed to an alliance with Thinkhaya, formalizing it with a marriage of state to Thinkhaya's daughter, Saw Min Aung. He also accepted Anawrahta's vassalage by marrying Anawrahta's daughter.Yazawin Thit Vol. 1 2012: 275
Alliance's expansion (1427–1429)
Initially, the developments in the south went unchallenged by Ava. Thado's regime was completely preoccupied by the Minye Kyawhtin rebellion, which threatened the Ava capital region itself. Indeed, by early 1428, Minye Kyawhtin had advanced to Pinle, just 70 km from Ava.Yazawin Thit Vol. 1 2012: 276Hmannan Vol. 2 2003: 66
This allowed the southern alliance to acquire territory unimpeded. For Ran, his primary target was Tharrawaddy, Ava's southernmost district, which jutted into the Irrawaddy delta. He had long desired control over the district, having claimed it in 1422. With Paungde, the district north of Tharrawaddy, already under his control, Ran had no trouble occupying Tharrawaddy in 1427. His territory now extended to Paungde, approximately 65 km south of Prome (Pyay), Ava's main southern city and fortress. He added Tharrawaddy to Anawrahta's portfolio.
Thinkhaya too expanded his reach. While Ava forces besieged Pinle during the 1428–1429 dry season, Toungoo forces, aided by Taungdwin troops, seized the five irrigated districts of Yamethin region immediately north of Toungoo. Subsequently, the Shan state of Yatsauk, another former Ava vassal, joined the alliance to defend the region.Yazawin Thit Vol. 1 2012: 276–277Hmannan Vol. 2 2003: 67 Buoyed by their success, Toungoo forces later raided Pin, Natmauk and Thagara, districts immediately south of the Ava capital region, and brought much needed conscripts back to Toungoo.
Ava's nonresponse Meanwhile, Ava's Pinle campaign had failed. By early 1429, the Ava court was increasingly pessimistic about defeating the rebellions militarily. In a change of strategy, Thado accepted the court's recommendation to abandon the peripheral vassals in the Shan states in order to focus on the more central regions of Pinle and Yamethin. The court sent embassies to persuade the sawbwas of Onbaung and Yatsauk to withdraw their support of Minye Kyawhtin and Thinkhaya, respectively in exchange for Ava's recognition of those states. The overtures failed.
Thado now effectively gave up on reunifying the kingdom militarily. His priority became defending the narrow Irrawaddy river valley he controlled. He also developed an interest in constructing religious monuments, ordering the construction of a new Buddhist stupa, the Yadana Zedi Pagoda, to house religious relics he had received from Ceylon.Aung-Thwin 2017: 87 However, after Shin Saw Pu's successful escape to Pegu in late 1429, the court reminded Thado that Ava's main fortress Prome, surrounded by Launggyet Arakan, Hanthawaddy and Toungoo on three sides, was now highly susceptible to attack. In response, Thado appointed his second son Thihathu as governor of Prome.Hmannan Vol. 2 2003: 68–69
Alliance's next target As the Ava court suspected, the alliance had been eyeing Prome. Following his successful 1428–1429 campaigns, Thinkhaya proposed Ran a plan to jointly attack the southern fortress. (According to G.E. Harvey, Thinkhaya sought a much larger commitment from Ran—to install him on the Ava throne in exchange for his vassalage: "Put me on the throne of Ava, and I will be your vassal." However, the quote's source is unclear as royal chronicles do not mention Thinkhaya aiming for the Ava throne.)
Initially, Ran was reluctant to start a new war with Ava. He maintained good relations with Ava at least until mid-1429 when he sent a naval flotilla to escort the Ceylonese relics destined for Thado's new pagoda up the river to Prome. Ran changed his mind only after his sister Shin Saw Pu successfully returned to Pegu.Hmannan Vol. 2 2003: 68 The king then agreed to a limited campaign to capture Prome in the following dry season.
War Battle of Prome
By the end of the rainy season of 1430, the alliance's joint invasion force massed for a three-pronged pincer movement against Prome. From the south, the Hanthawaddy navy (5000 troops, 50 war boats, 20 transport boats) commanded by Binnya Ein, would attack Prome via the Irrawaddy river. The Hanthawaddy army (5,000 troops, 100 cavalry, and 30 elephants) under the command of Smin Bayan would concurrently invade from their Tharrawaddy base. King Binnya Ran served as the overall commander-in-chief, sailing with the flotilla on his royal barge, Karaweik. Meanwhile, the Toungoo army, led by Thinkhaya, would advance from the east, crossing the Pegu Yoma range via the Konkhaung (ကုန်းခေါင်) Pass.
The Ava high command was unaware of the impending invasion until the last minute. Thado had spent the past year devoting significant resources to constructing his new pagoda, and had not mobilized additional troops for major campaigns. Governor Thihathu was therefore forced to rely, at least temporarily, on Prome's strong defenses, which included high brick walls and jingal wall guns. Thihathu rushed to stockpile the manpower and provisions within the city walls.
In October 1430, the joint invasion by Pegu and Toungoo began. The Hanthawaddy navy advanced unimpeded, and successfully blockaded Prome. Both the Hanthawaddy and Toungoo armies met minimal resistance as Prome's forward forces quickly retreated into the city. However, the invasion forces were kept at bay by the city's jingal wall guns, and the siege began.
Negotiations At Ava, Thado scrambled for options. The Ava court called up mobilizations for the southern front but also advised the king that he lacked sufficient troops to break the siege in the south, and defend the capital region from other rebel forces (Pinle, eastern and northern Shan states as well as Yamethin). They recommended negotiating directly with Ran to convince him to withdraw Pegu's support for Toungoo. This proposed strategy paralleled the earlier attempts to negotiate with Onbaung and Yatsauk regarding the Pinle and Yamethin rebellions. Thado reluctantly agreed, and dispatched the envoy Tuyinga Bo to the Hanthawaddy camp. Bo informed Ran that Thado would negotiate directly, monarch-to-monarch, provided that Thinkhaya was excluded. Ran was receptive to the proposal but wanted more than a simple alliance with Ava. He sent an embassy led by Maha Thamun to Ava with his terms.
Ran's demands were poorly received in Ava. The primary demand required Thado to formally acknowledge Ran's 1427 annexation of Tharrawaddy and Paungde. Thado angrily ordered Maha Thamun executed before his Chief Minister Yazathingyan talked him out of it.Maha Yazawin Vol. 2 2006: 68Hmannan Vol. 2 2003: 72 Thado specifically objected to ceding Paungde. The Ava king kept the Hanthawaddy delegation waiting, and continued the pagoda construction to its completion on 27 January 1431. Only after the completion ceremony did Thado turn his attention to the war. Circa early February 1431, Ava land and naval forces finally arrived at Prome. The army (5000 troops, 800 cavalry and 50 elephants) was led by Governor Thihapate I of Pakhan. Thado personally commanded the navy (8000 troops, 50 war boats, 80 transport/cargo boats).