In the spring of 1656, in the third year of Xia Wu'an and the fifth year of Qin Baoguo, Mangda, the king of Donghu, officially declared war on Sun Qin on the grounds of recovering the lost territory, and sent 100,000 troops to attack Mengnaicheng, which was taken by Sun Qin in the east.

A few days later, the Ayutoya Kingdom in the south of the Lanna Kingdom also announced that it would join the war and sent troops to attack the Lanna Kingdom.

In just one month, Ayutthaya's army conquered Chiang Mai, the capital of Lanna, and turned Lanna into its own vassal, and then the army continued to move north, storming the native city of Sun Qin.

For a time, Sun Qin fell into the dilemma of attacking from both sides, but Sun Kewang did not panic because of this, after careful consideration, he decided to retreat as an advance, and took the initiative to meet the Burmese army outside Meng Nai City, pretending to be defeated and luring the Burmese army to pursue.

When the Burmese army saw that the Qin army was defeated, they thought that the Qin army was afraid of the huge strength of the Burmese army, and they did not have much suspicion, so the chief general of the Burmese army ordered a pursuit and fell head-on into the ambush circle set up by the Qin army.

When the chief general of the Burmese army realized that it was too late when he was scheming, he only heard the sound of artillery around him, and the Qin army came out of the surrounding dense forest like a tide, and soon the Burmese army was shocked to pieces, the Burmese army was invincible and resisted, and returned defeated, and the soldiers and horses who were ambushed were almost completely annihilated, and the main general of the Burmese army was killed in the chaos.

In order to deter the Burmese people, Sun Kewang did not hesitate to order the captured Burmese prisoners of war to be killed, after this battle, tens of thousands of Burmese soldiers were killed, after the news was transmitted back to the capital Ava, the Burmese king Mangda's face turned pale when he heard the news, sweat was like rain, and he almost fainted.

The ministers of the court and the central government have written to ask the king to strike and beg for peace, but Mangda is unwilling to stop the army like this, he will take the Lanna Kingdom as a condition for Ayuthaya to send troops, if the army is stopped at this time, tens of thousands of troops will be killed, and he will lose a vassal country, then he is really a big loss.

On the other side, the news of the Qin army's defeat of the Burmese army in Meng Nai spread rapidly, and the Ayutthaya army did not dare to continue to go north after getting the news, and it happened that at this time, the king of Ayuthaya King Basethong died of illness, and the new monarch Zhaofa guessed that he succeeded to the throne, the latter was still in infancy and was unable to decide on military affairs, and its court regent agreed that it should be accepted when it was good, and negotiated peace with Sun Qin.

At this time, Sun Kewang was on the front line of Mengnai, and his line was in the custody of the crown prince Sun Zhengqi, and the prince considered that Sun Qin was still weak and inconvenient to start a war with two regional powers at the same time, so he agreed to negotiate peace with Ayuthaya, but the peace was not unconditional, and as a price, the kingdom of Ayuthaya needed to provide 100,000 taels of silver and 150,000 stones of grain and grass at one time.

The Ayuthaya people were also shocked by Sun Kewang's prestige, and did not dwell on this issue more, and hurriedly prepared for the delivery of silver, grain and grass with the Qin army, and the two countries ended the state of war.

Now that the enemy in the south was solved, Sun Kewang was furious and decided to teach the Burmese a bitter lesson, he divided his army into two parts, and personally led an army of 20,000 to capture Niangrui, and then marched to Ava City by way of Jinda and Ye'an, and attacked Wentun and Bagan with the general Wang Ziqi leading the division.

The speed of the Qin army was extremely fast, and the Burmese army was disheartened and had no intention of continuing to fight, and was quickly defeated under the offensive of the Qin army, and the Qin army rushed all the way to Ava City.

At this time, the Burmese king Mangda finally knew the fear, and he hurriedly sent an envoy to Yunnan, asking the Celestial Empire to send troops to rescue him, and at the same time gather troops and horses around the capital to defend the capital.

At the end of April, the Qin army defeated the Burmese army one after another, and the troops approached the city of Ava, and then launched a siege on the city of Ava, but because the Qin army did not carry a large number of artillery, the siege progress was slow.

But even so, the rumbling cannons and shouts of killing were enough to make the Burmese monarchs and ministers extremely frightened, for fear that the Qin army would break through the city wall and enter the city in the next second.

Extremely frightened, Mangda could only pray to the Qin army outside the city for peace talks, but Sun Kewang thought that it was only a matter of time before the army conquered Ava, and when he entered the city, he would have everything he wanted, so he refused the Burmese king's request for peace talks and ordered the siege to continue.

At the same time, Yunnan had already received a request for help from the king of Burma, but Yunnan did not rush to send troops, but wrote to the imperial court to ask whether to send troops.

At the same time, Li Mingzhong, the general soldier of Yunnan on the border of Menggen, and Liu, the duke of Shu

Wenxiu also wrote to the imperial court successively, asking the imperial court to issue an order to send troops to the south to conquer Sun Rebellion.

The southwest has been pacified for a long time, and the opportunity for them to brush up on their military exploits is in front of them, how can they be willing to let it go?

The Yunnan Sandao Song was sent to Jiangning successively under the whip of the fast horse, which immediately caused an uproar in the court, and Mu Tianbo, the prince of Qianguo, who had been staying in Jiangning, was the first to come out, believing that the imperial court should send troops to defeat Sun Reyi, recover the lost territory of Meng Gong, and take this opportunity to consolidate the influence of the imperial court in the southwestern countries.

His proposal was seconded by many courtiers, and Su Yan adopted his proposal and ordered Liu Wenxiu, the Duke of Shu, to be the general of the southern expedition, and Li Mingzhong, the general of Yunnan, to lead the army south to defeat Sun Kewang.

The holy decree was issued, and it was quickly sent to Yunnan in an expedited manner of 800 li, but by the time the holy decree was delivered, it was already too late.

After besieging the city of Ava for half a month, the Qin army finally entered the city on May 10 and captured the Burmese king Mangda and a number of royal families, nobles, and ministers.

After attacking the city of Ava, the Qin army plundered the city, and the rich capital of the Toungoo Dynasty was severely damaged, and all the rich wealth accumulated in the city was plundered by the Qin army.

Sun Kewang was angry at Mangda's attack, and at this time, Mangda's brother Mangbai took the initiative to find Sun Kewang and asked Sun Kewang to abolish Mangda and make him king, and he swore allegiance to Sun Kewang for generations.

After much deliberation, Sun Kewang agreed to Mangbai's request, ordered Mangda to be hanged, sunk his body into the Mino River with the queen and children, and then canonized Mang Bai as the king of Donghu, who immediately vowed to submit to Great Qin forever.

After that, Sun Kewang asked Mang Bai for a large amount of silver and grain and grass, and ordered him to cede the Mengnai region, and then led the army to return to the court, but when he passed through Mengnai, he received a tip from the north that favored his Tusi:

Xia Jun was pulled.

As the holy decree said, the Xia army took Liu Wenxiu, the Duke of Shu, as the general, and Li Mingzhong, the Marquis of Haikang, as the deputy, and the two armies sent troops south together.

Liu Wenxiu, the Duke of Shu, personally led his headquarters army of 30,000 to the south along the Salween River, intending to cut off Sun Kewang's way back to Meng Gen, while Li Mingzhong, Marquis of Haikang, led an army from Meng Liansi to storm Meng Yang, the gateway to Meng Gen.

The Qin army deployed a certain number of troops to defend Meng Yang, so the Xia army failed to conquer this place at the first time, and the soldiers and horses stationed in the southwest almost did not accept the reorganization of the army, which was mainly based on cold weapons, and the Xia army attacked for several days before finally conquering Meng Yang.

Subsequently, Li Mingzhong continued to lead the army south, and in Menggen Mansion, the crown prince Sun Zhengqi immediately gathered the troops and people walking around after receiving the news, cut down trees to build fortification equipment, intending to defend the city, and held it until Sun Kewang led the army back.