The Ava–Hanthawaddy War (1422–1423) () was the fourth major conflict of the Forty Years' War, fought between Ava and Hanthawaddy Pegu in present-day Myanmar. The war was precipitated by a succession crisis in Pegu, following the death of King Razadarit in 1421. King Thihathu of Ava initially intervened on behalf of Prince Binnya Kyan but later ended his involvement by forming an alliance with Crown Prince Binnya Ran.
The conflict began in early 1422 when Ava forces helped Kyan retake his fief of Dala. However, due to rampant looting by the Ava troops, Kyan quickly switched allegiance back to his brother, King Binnya Dhammaraza, and drove his former allies out. The Hanthawaddy power struggle soon resumed when Crown Prince Ran seized control of Dagon, and claimed Ava's southernmost district of Tharrawaddy. Thihathu responded by launching a larger, retaliatory invasion of the Irrawaddy Delta in November 1422. When Ava forces laid siege to Ran's "capital" of Dagon, Ran sued for peace, offering an alliance and a marriage of state to his sister, Princess Shin Saw Pu. Thihathu, primarily interested in restoring royal prestige and securing his border, accepted the terms and withdrew his forces in early 1423.
The peace was short-lived. Hanthawaddy was reunified under Ran's leadership by 1424, while Ava was plunged into a prolonged succession crisis following Thihathu's assassination in 1425. Ran exploited Ava's internal chaos by allying with the rebel vassal Toungoo and seizing Ava's southern districts of Tharrawaddy and Paungde by 1427. The allies subsequently pushed farther north by attacking Prome, starting the Ava–Hanthawaddy War (1430–1431).
Background This was the fourth war between Ava and Hanthawaddy Pegu since 1385, occurring shortly after the conclusion of third war (1408–1418). In that decade-long war, Hanthawaddy, Ming China and its vassals (Maw (Mong Mao) and Hsenwi) jointly attacked Ava in response to Ava's expansion into Launggyet Arakan and the Shan states.Htin Aung 1967: 91Aung-Thwin 2017: 78–79 The war ended without a formal peace treaty between Ava and either Hanthawaddy or China.
The unofficial peace held for the next three years until the deaths of both Minkhaung I and Razadarit in late 1421.Yazawin Thit Vol. 1 2012: 264–265 At Ava (Inwa), Crown Prince Thihathu succeeded without incident. However, the succession at Pegu (Bago) was not orderly, plunging the kingdom into a succession crisis.Htin Aung 1967: 93Harvey 1925: 95, 115
The crisis signaled the likelihood of external interference, a pattern established in previous conflicts. In the first war (1385–1391), King Swa Saw Ke of Ava unsuccessfully tried to replace the new king Razadarit of Hanthawaddy.Harvey 1925: 82–85Htin Aung 1967: 88 Likewise, Razadarit unsuccessfully attempted to gain submission of Ava's new king Minkhaung in the second war (1401–1403).Aung-Thwin 2017: 254–255Fernquest Spring 2006: 10–11
Past interferences were rooted in strategic and economic reasons.Mi Mi Hlaing 2018: 7 Ava sought to restore the erstwhile Pagan Empire,Htin Aung 1967: 88 and fought to maintain control of its southernmost towns down to Tharrawaddy (Thayawadi) in order to control the "trade along the Irrawaddy as far south as possible".Harvey 1925: 90 Conversely, Pegu attempted to establish a larger strategic depth, by trying to seize Ava's southernmost districts of Tharrawaddy, Gu-Htut as well as Prome and Toungoo farther north in the previous wars.
Prelude to war Pegu succession crisis The crisis began immediately after Razadarit's burial. Because the late king had not appointed an heir-apparent, his three remaining sons— Prince Binnya Dhammaraza, Prince Binnya Ran and Prince Binnya Kyan—vied for the throne. The chief rivals were the two eldest sons, Dhammaraza and Ran, who were born only a few months apart by different queens. Chief Minister Dein Mani-Yut did not take sides between Dhammaraza and Ran.Shwe Naw 1922: 49 However, Dhammaraza, who had claimed the throne by primogeniture, apparently garnered enough support at court to be crowned king at Pegu (Bago).Yazawin Thit Vol. 1 2012: 267Hmannan Vol. 2 2003: 55Pan Hla 2005: 2005: 359
A chaotic rebellion and shifting alliances ensued. Ran and Kyan immediately revolted out of their fiefs, Syriam (Thanlyin) and Dala (Dala–Twante), respectively. Initially, Ran and Kyan formed an alliance but no one trusted the other. Kyan went on to seize Dagon (modern downtown Yangon) across the river from Syriam. This brazen land grab convinced Ran to accept Dhammaraza's offer to become the heir apparent.Phayre 1967: 81Aung-Thwin 2017: 261 Kyan was now isolated. Dhammaraza then successfully sent an army to take Dala. Holed up in Dagon, a desperate Kyan sent a letter to Thihathu, pledging his allegiance in exchange for military help "to recover his rightful fief, Dala."
Thihathu's decision Kyan's request represented the first foreign policy decision for Thihathu. According to the chronicles, the new king had done little governing. He reportedly spent much of his time with his new queen Shin Bo-Me, who happened to be his father's favorite queen. To be sure, the king, who served as governor of Prome (Pyay) from 1413 to 1416, had kept a close eye on the southern border. He had just appointed new governors in Prome and Tharrawaddy. According to chronicle reporting, Thihathu did not entertain the idea of a regime change as his grandfather, father, and eldest brother had before him. In the end, the king opted for limited involvement to keep Kyan's rebellion afloat. He sent down two regiments (2000 troops, 20 war boats) via the Irrawaddy river, led by commanders Zeyathingyan and Tuyin Ponnya.
Dala campaign (c. February–March 1422)
Circa February 1422, the small Ava flotilla crossed the border into the Irrawaddy delta. Their battle plan relied on the intelligence that customary Hanthawaddy defenses had not been organized. The flotilla advanced unimpeded down the Hlaing River towards Dagon. Despite their relatively small size, they successfully lifted the siege at Dagon.
At Dagon, Kyan targeted to regain his fief. The combined Ava and Kyan's regiments launched a joint attack on Dala by land and river. Dala's defenses, led by Smin Maw-Khwin and Smin Pun-Si, resisted but ultimately fell. Following the victory, Binnya Kyan was so angered by the commanders' fierce resistance that he had both of them executed.
However, the alliance soon fractured. The reason was the blatant looting and deportation of townsfolk by the Ava troops. Disgusted with his allies, Kyan quickly entered into secret talks with Dhammaraza, and the brothers soon reached an agreement. In exchange for Kyan's allegiance, Dhammaraza agreed to restore Kyan to his post at Dala, with the promise of a substantial future fief.Phayre 1873: 120
A joint operation by the brothers ensued. Dhammaraza sent another army to Dala. Meanwhile, Kyan treacherously engineered the murder of principal Ava officers inside Dala, including Commander Zeyathingyan. The remaining Ava forces, led by Tuyin Ponnya, were forced to withdraw in disarray. In the end, only about half the Ava troops managed to return to their base at Prome.
Interlude (c. April–October 1422) Ava response
At Ava, Thihathu was oblivious. Despite his rash decision to intervene in Pegu's affairs, the king had not closely followed the events. According to the chronicles, he continued spending so much of his time with Queen Bo-Me that his chief queen consort, Saw Min Hla, moved out of the palace. The disaster at Dala now forced him to respond; royal prestige was at stake. He ordered a mobilization for a sizable retaliatory campaign for the upcoming dry season.Yazawin Thit Vol. 1 2012: 267–268
Machinations in Hanthawaddy Meanwhile, at Pegu, the three brothers reached a power-sharing agreement. King Dhammaraza granted Bassein–Myaungmya Province (modern Ayeyarwady Region) in the west to Crown Prince Ran, and Martaban Province (modern Mon State and southern Kayin State) in the east to Prince Kyan. The king retained direct control only over central Pegu Province (modern Yangon Region and southern Bago Region).
The arrangement soon broke down. While Kyan was satisfied, Ran was not. As soon as Kyan left for Martaban, Ran brazenly occupied Dagon, the territory belonging to Pegu. However, Dhammaraza did not respond to Ran's "ungrateful conduct" because he was hampered by various court factions.Phayre 1967: 82
Tharrawaddy question Ran's land grab may have also breached Ava's territory. According to the Slapat Rajawan chronicle, Ran also took over Tharrawaddy, which belonged to Ava at the time. However, the main chronicles, which narrate primarily from the perspective, do not mention Ran's occupation of Tharrawaddy at all. The omission is significant because the territory would have been listed as part of Ava's casus belli. Historians Arthur Purves Phayre and Michael Aung-Thwin, following the Slapat, conjectured that Ran controlled Tharrawaddy.
At any rate, on the eve of Ava's dry season invasion, Ran controlled the most territory: the entire Irrawaddy delta as well as the southern Pegu province, and perhaps Tharrawaddy. King Dhammaraza, meanwhile, controlled only the area immediately surrounding the capital.
Ava invasion of Hanthawaddy (November 1422–January 1423)
Preparations
The Ava battle plan was similar to the previous retaliatory campaign of 1417–1418. As in that campaign, they opted to open only the Irrawaddy Delta front, bypassing the Sittaung front towards Pegu. The Ava command had assembled a joint land and naval strike force, like the previous campaign. The force consisted of an army (8000 troops, 500 cavalry, 30 elephants) commanded by Governor Thado of Mohnyin, and a navy (6000 troops, 50 war boats, 50 ironclad hlawga transport boats, 50 cargo boats), commanded by Prince Min Nyo of Kale.Yazawin Thit Vol. 1 2012: 268Hmannan Vol. 2 2003: 56 The total strength of the strike force was 14,000 troops, slightly smaller than the 16,000 troops fielded in the 1417–1418 campaign.Yazawin Thit Vol. 1 2012: 264Hmannan Vol. 2 2003: 51
On the Hanthawaddy side, no unified, coordinated defense existed. Since power was split among the three rivals, Ran was left to defend the delta on his own while Dhammaraza concentrated on the Sittaung front. (Kyan's Martaban province did not share a border with Ava.) Given his limited manpower on the delta front, Ran's battle plan was to resist from inside the key fortified towns across the delta (and perhaps Tharrawaddy). He kept most of his manpower in his "capital" of Dagon.
Invasion
The invasion began in . The invaders first attacked the Khebaung fort, which served as the gateway into the delta. The small garrison resisted but the fort fell soon after. An Ava regiment was assigned to guard the strategically located fort. Ava forces then marched to the western delta, and captured Bassein with minimal resistance. Nawrahta of Salin was appointed the military governor to hold the western delta. Ava forces next marched to the eastern delta. Ran's forces defended Dala briefly before retreating to Dagon. Ava forces converged on Dagon, from Hlaing (modern Taikkyi) in the north and from Dala in the west.
However, the siege made no further progress. Dagon was heavily fortified, well provisioned, and had sufficient troops. Ava forces now prepared for a long siege as they had in the previous campaigns.
Peace proposal About one month into the siege, , Ran made a peace offer. He sought an alliance with King Thihathu, and was prepared to offer his younger sister Princess Shin Saw Pu in a marriage of state.Aung-Thwin 2017: 261–262 The Ava army commander-in-chief, Thado of Mohnyin, relayed Ran's letter to Thihathu.