Minkhaung I of Ava (Burmese: ပထမ မင်းခေါင် [pətʰəma̰ mɪ́ɰ̃ɡàʊɰ̃]; also spelled Mingaung; 1373–1421) was king of Ava from 1400 to 1421. He is best remembered in Burmese history for his epic struggles against King Razadarit of Hanthawaddy Pegu in the Forty Years' War (1385–1424). As king, Minkhaung continued his father Swa Saw Ke's policy to restore the Pagan Empire. Under the military leadership of his eldest son Minye Kyawswa, Ava nearly succeeded. While he ultimately failed to conquer Hanthawaddy and Launggyet Arakan, he was able to bring in most of cis-Salween Shan states to the Ava orbit.
The future king was born in a small village called Gazun-Nyeint (present-day northern Sagaing Region) on 13 September 1373. His father King Swa Saw Ke of Ava had met his commoner mother Saw Beza earlier in the year during a military campaign against Mohnyin. Chronicles say that after giving birth to the child, Beza showed up at the Ava palace to present the male son, as instructed to by the king. The child was named Min Swe (မင်းဆွေ [mɪ́ɴ sʰwè]). The king made Beza a junior queen, and had two more children with her: Theiddat and Thupaba Dewi.
Min Swe grew up in Ava (Inwa) until he was eight. His life at the palace was not all well. Their older half-brother Tarabya, who was born to a senior queen, constantly bullied both Swe and Theiddat. The bullying became a serious problem, and in 1381/82, the king had to send away Swe and Theiddat to a small monastery near Pinle to study under the chief primate (Thinga-Yaza). The two princes studied under the learned monk, and traveled around the region, including Taungdwingyi, Minbu, Ngape and Padein, with their attendants.
Circa April 1385, Swa appointed Tarabya his heir-apparent. The king kept Swe out of Tarabya's reach, and appointed his 11-year-old son governor of Pyinzi, a small town about 85 km southwest of Ava. He also gave Swe command of the 33-member Pyinzi cavalry. Swe would rule Pyinzi for the next 15 years. Chronicles have little information about Swe's period as governor except that his rivalry with Tarabya continued, and that the rivalry may have cost Ava's best chance of defeating Hanthawaddy Pegu.
In 1385, the king ordered his two eldest sons to lead a two-pronged invasion of the southern kingdom in what would become known as the Forty Years' War. Tarabya commanded the First Army (7000 infantry, 500 cavalry, 20 elephants) while Swe led the Second Army (6000 infantry, 500 cavalry, 20 elephants). The two princes were advised by Ava's best commanders, including Thilawa of Yamethin and Theinkhathu Saw Hnaung. The Ava command expected an easy victory over an overpowered opponent. But Ava forces could not break through well-organized Peguan defenses for five months. Then, King Razadarit of Hanthawaddy made a tactical error by coming out of his fortified capital to attack Ava positions near Pankyaw. Tarabya's army pounced, driving back and pursuing Razadarit's army. Meanwhile Swe's army had positioned in the path of retreat of the Hanthawaddy army. Tarabya, the overall commander-in-chief, sent a messenger, ordering Swe to hold his position and not to engage Razadarit until his army could reach the scene. But Swe ignored the order and the advice of his seasoned commanders, and ordered his troops to engage. Razadarit's army defeated Swe's premature attack, and got back inside Pegu. Five days later, with the rainy season approaching, the invasion was called off.
Ava would come to rue the missed opportunity. Swa kept Swe from the next invasion in the following dry season. Swe was assigned to guard the capital while Swa and Tarabya invaded the southern country again. The second invasion fared no better. Razadarit committed no more errors, and hunkered down. Ava troops could not break through Pegu's defenses and had to retreat before the rainy season arrived. Swe was to get his chance again to go to the front in the 1390–91 campaign. But this time, he commanded just a regiment, and was directly under the command of Tarabya. At any rate, their army could not break through the Pegu defenses at Pankyaw although the campaign ended in a truce.
In 1389/90, Swe was married to Princess Shin Mi-Nauk, daughter of the chief of Mohnyin, in a marriage of state. The marriage was part of the effort by Ava and Mohnyin to mend their fences after the 1387–88 war between the two states. On the advice of Chief Minister Min Yaza, King Swa selected Swe to marry Mi-Nauk. While the peace with Mohnyin did not last—Ava and Mohnyin were to fight another war just three years later—the marriage between Swe and Mi-Nauk lasted. The couple had four children at Pyinzi: Minye Kyawswa, Saw Pyei Chantha, Minye Thihathu and Minye Kyawhtin.
In April 1400, King Swa Saw Ke died and Tarabya ascended the throne. The new king kept his two half brothers at an arm's length. Neither Swe nor Theiddat controlled a sizable army. When Tarabya became mentally unstable about five months into his reign, and other pretenders began circling the throne, Swe was not in a strong-enough position to challenge them. Soon after, Gov. Thihapate of Tagaung assassinated Tarabya, and tried to seize the throne. But the court executed the usurper, and offered the throne to Min Swe. But Swe was concerned about Gov. Maha Pyauk of Yamethin, who controlled a sizable army, and told the court to offer the throne to Pyauk instead. Theiddat implored Swe to reconsider. When his brother still refused, Theiddat took matters into his own hand. Theiddat and his small band of men ambushed Pyauk's much bigger army near Ava while Pyauk was not expecting. Pyauk was killed. Min Swe had been proclaimed king by 25 November 1400 (or 26 October 1400). He assumed the title of Minkhaung (မင်းခေါင်; "Foremost Lord" or "Paramount Lord").
Minkhaung spent his first year consolidating his power. He kept Min Yaza as chief minister, and appointed Yaza's son Pauk Hla governor Yamethin, and Yaza's son-in-law Thado Theinkhathu governor of Badon and Tabayin. He also appointed Theiddat governor of Sagaing with the title of Thiri Zeya Thura but stopped short of declaring him his heir-apparent. While Sagaing was a sizable province that used to be an independent kingdom, the younger brother was never satisfied with the reward, and held a "lingering resentment that would later rear its ugly head".
The succession crisis at Ava did not go unnoticed. The Arakanese raided western Irrawaddy towns. In Pegu, King Razadarit assessed that Minkhaung's hold on power was still weak, and planned to place a nominee of his own. It would be payback for Ava's attempts to dislodge him early in his reign. Throughout 1401, Razadarit prepared an invasion river-borne fleet that could transport not only troops but even horses and elephants. When the dry season began, Hanthawaddy forces invaded by the Irrawaddy river, attacking all the riverside towns and cities, including their main targets, Prome (Pyay) and Ava (Inwa).
The Forty Year's War had resumed after a 10-year hiatus. Initially, Hanthawaddy held the advantage. Ava did not have a navy that could challenge Pegu's massive flotilla. Ava forces had to defend inside the fortified towns along the river: Prome, Myede, Sagu, Salin, Pakhan Nge, Salay, Pagan (Bagan), Talok, Pakhan Gyi, Sagaing and Ava. The Pegu navy held complete control of the Irrawaddy (as far north as Tagaung) but the blockades were not enough to force a surrender. Minkhaung bought time by sending a delegation led by a learned Buddhist monk, Shin Zawtayanta, to broker a truce. The monk delivered a sermon that Razadarit used as a pretense to withdraw from Ava. Minkhaung's vassals now rallied around him. He was able to assemble a sizable force, which he sent after the rainy season to relieve Prome. The Ava army decisively defeated the invaders south of Prome on 26 December 1402, forcing Pegu to ask for terms about ten days after the battle.
Minkhaung sent an embassy led by Min Yaza to Pegu to negotiate a treaty. He wanted to exact a price from Pegu. After five months of negotiations, the two sides signed a peace treaty. The boundary of their kingdoms was fixed a little to the south of Prome. Pegu agreed to share the customs revenue of Bassein (Pathein), and supply 30 elephants annually. In return, Minkhaung sent his only sister Thupaba Dewi to be queen of Razadarit in a marriage alliance.