The Sino-Burmese War, also known as the Qing invasions of Burma or the Myanmar campaign of the Qing dynasty, was a war fought between the Qing dynasty of China and the Konbaung dynasty of Burma (Myanmar). China under the Qianlong Emperor launched four invasions of Burma between 1765 and 1769, which were considered as one of his Ten Great Campaigns. Nonetheless, the war, which claimed the lives of over 70,000 Chinese soldiers and four commanders, is sometimes described as "the most disastrous frontier war that the Qing dynasty had ever waged", and one that "assured Burmese independence". Burma's successful defense laid the foundation for the present-day boundary between the two countries.
At first, the Emperor envisaged an easy war, and sent in only the Green Standard troops stationed in Yunnan. The Qing invasion came as the majority of Burmese forces were deployed in their latest invasion of Siam. Nonetheless, battle-hardened Burmese troops defeated the first two invasions of 1765–1766 and 1766–1767 at the border. The regional conflict now escalated to a major war that involved military maneuvers nationwide in both countries. The third invasion (1767–1768) led by the elite Manchu Bannermen nearly succeeded, penetrating deep into central Burma within a few days' march from the capital, Ava (Inwa). But the bannermen of northern China could not cope with unfamiliar tropical terrains and lethal endemic diseases, and were driven back with heavy losses. After the close-call, King Hsinbyushin redeployed his armies from Siam to the Chinese front. The fourth and largest invasion got bogged down at the frontier. With the Qing forces completely encircled, a truce was reached between the field commanders of the two sides in December 1769.
The Qing kept a heavy military lineup in the border areas of Yunnan for about one decade in an attempt to wage another war while imposing a ban on inter-border trade for two decades. The Burmese too were preoccupied with the Chinese threat, and kept a series of garrisons along the border. Twenty years later, when Burma and China resumed a diplomatic relationship in 1790, the Qing unilaterally viewed the act as Burmese submission, and claimed victory. Ultimately the main beneficiaries of this war were the Siamese, who reclaimed most of their territories in the next three years after having lost their capital Ayutthaya to the Burmese in 1767.