For most of her history, Vietnamese kings sometimes recognized the Chinese Emperor as their feudal lord, while ruling independently in their own land. This had been the case throughout the reign of the Later Lê Dynasty. However, the Tây Sơn uprising broke out in 1771, and the Lê Dynasty was overthrown by Tây Sơn army in 1787. The last emperor, Lê Chiêu Thống, fled to China and appealed to Emperor Qianlong for help. In 1788, a large Qing army was sent to Vietnam, in order to restore Lê Chiêu Thống to the throne.