The Qing dynasty saw its height of power under three exceptional emperors: Kangxi, Yongzheng and Qianlong. Under their rule, China saw huge advances in literature and military technology. Because the Qing rulers weren't ethnic Han Chinese, they imposed tight controls to maintain their power. However, the Qing had to work closely with Han Chinese scholars and within the Confucian bureaucratic framework to rule their empire effectively. The Qing emperors expanded the frontiers of their empire and consolidated the borders of what would become modern China.
Nevertheless, beneath the aura of splendor began a rot that would destroy the framework of the empire. Overpopulation and rampant corruption created instability. Population and economic pressures forced many into poverty. With no future, many chose to revolt.
Foreign encroachment from Western powers arrived a time when the Qing dynasty was on the downward trend of the dynastic cycle. In the 19th century, Britain began exporting opium to China to reduce a trade imbalance that had arisen with British demand for tea, silk and porcelain. China's wealth was drained as the nation became addicted to opium. The Qing government's restrictions on the opium trade led to the first Opium War in 1840. The Qing was thus forced to face modernity.