What were the specific reasons for the expedition to Burma during the Qianlong era? How does it end?

In the early Qing Dynasty, there was no formal official contact between China and Myanmar for a long time. However, the two countries were geographically adjacent and people-to-people exchanges were very frequent. In the eighteenth year of Qianlong's reign, through the introduction of Wu Shangxian, the owner of Yunnan Maolong Factory, who had close relations with Myanmar, the two countries began to have contacts. The Qing government allowed Myanmar envoys to come to China, which was the beginning of formal contact between the two countries. But this good start was interrupted by the civil strife that broke out in Myanmar. Starting from the 20th year of Qianlong's reign, the Burmese army continued to harass the chieftains such as Geng Ma and Meng Lian of the Qing Dynasty. In the 30th year of Qianlong's reign, the Burmese army even invaded Lanyanba on the Jiulong River in Yunnan and occupied Checheng. Liu Zao, the governor of Yunnan and Guizhou, sent troops to conquer, but due to improper command, he was defeated. In the first month of the thirty-first year of Qianlong's reign (1766), the Qing government sent a great scholar, Yang Yingju, to move from Shaanxi-Gansu to Yunnan. After Yang Yingju took office, he commanded the army to repel the Burmese army's invasion and regain the lost territory. However, Yang Yingju was arrogant and underestimated the enemy because of this, and was greedy for merit. After he moved to Yongchang in Pu'er, he wrote to the king of Myanmar, stating that he would lead an army of hundreds of thousands to conquer and ask Myanmar to surrender. So Myanmar raised troops to fight, and fighting between the two sides resumed. The Qing army failed in several battles, and the Burmese army took the opportunity to invade Yunnan. Emperor Qianlong was furious when he heard the news and ordered Yang Yingju to be arrested and sent to the capital to die. In the 32nd year of Qianlong's reign, he sent General Mingrui to divide his troops into five groups to conquer Burma. At the beginning of the war, the Qing army won consecutive battles and made rapid progress. It was approaching the capital of Myanmar, Ava (today's Mandalay, Myanmar). However, after all, it was advancing alone and had no food and grass. It was finally defeated in February of the next year and retreated. Ming Dynasty Rui also committed suicide.

Emperor Qianlong was shocked by the news of the disastrous defeat of the Qing army. Seeing that the military situation was urgent, he "must have important ministers to go to supervise and supervise the dispatch", so he appointed Fu Heng as manager, and Ali Gun and A Gui as deputy generals. Shuhede was the counselor and minister in charge of the conquest of Burma. In February of the thirty-fourth year of Qianlong's reign, Fu Heng led more than 13,600 Manchu and Mongolian soldiers to the expedition. Before leaving, Emperor Qianlong personally awarded him the imperial seal in the Hall of Supreme Harmony and gave his own armor to Fu Heng to express his trust and hope in him.

In March of this year, Fu Heng arrived in Yunnan. In April, he went to Yongchang and Tengyue to inspect the situation and start preparations for the war. He learned that the Burmese army's defense "exclusively relied on Muzha" and that "the Qing army had always used ordinary guns and artillery to capture it, but to no avail", so he "interviewed people who are good at making cannons in the Maolong factory. In the future, when they march into the army, each soldier's bedding will be made of copper, A pound of iron can be used to cast a cannon secretly at any time when the fence is attacked, so as to catch the enemy by surprise." He also gathered the generals to discuss the strategy of entering the army. In view of the fact that General Minh Shwe only advanced by land in the past, and the Burmese side was able to concentrate its forces on defense, but suffered a defeat, Fu Heng decided to advance simultaneously by land and water. Because Awa, the capital of Myanmar, is to the west of the Great Jinsha River, and if one enters via the East Road through the Xiye River, Awa will still be across the river. Therefore, it was decided to go out of Hexi via the Jiajiu River (also known as Lanjiu River, or Betelang River) and take the road Meng Gong (today's west of Myitkyina, Myanmar) and Mengyang (today's Myitkyina, Myanmar) went straight to Awa, which was the main army; all the way went from the east bank of the Irrawaddy River to the south via Mengmi (today's Jieji, Myanmar). This is the partial division: the other route is from the Irrawaddy River, going down the river, and first building ships in Manmo (now Bhamo, Myanmar) to communicate with the first two armies, strengthen their momentum, and supply the needs of the two armies.

But in order to realize the policy of advancing on both land and water, we must first solve the problem of ships. Long before Fu Heng arrived in Yunnan, Emperor Qianlong had plans to build a ship and sent his deputy general Ali Gun to handle the matter. However, Aragon complained that "the journey through the outer gorge is very dangerous, the boats are impassable, and there are no offices along the river." Later, Fu Xian and Zuo Santai were ordered to investigate the actual situation, and "what they said was the same as Aragon." In this way, shipbuilding had to be put on hold for the time being. After Fu Heng arrived in Yunnan, he inquired the local residents in detail and learned that Wenggu Mountain near Manmo had more trees, and that the Bison Dam next to this mountain had a cool climate and was free from miasma, making it a good place for building ships. So Fu Heng He sent Fu Xian to supervise the transportation of materials and ordered craftsmen from Huguangwei to build ships. Soon, a group of ships arrived. Emperor Qianlong was very happy when he heard the news. He awarded him a special award and wrote a poem "Building a Boat" to commemorate this move.