5. The Qing Conquest of the Ming took almost 70 years, costing the Chinese nation more than 25,000,000 lives
The Ming-Qing transition, also known as the Manchu conquest of China, was a sustained period of conflict between the Qing dynasty of Northeastern China and the Ming dynasty of Southern China. Highly unpopular among the peasantry, with the “Seven Grievances” listed against the Ming Emperor, in 1618 the Manchu chieftain Nurhaci began an armed rebellion. Seizing several major cities from the Ming, including Shenyang to serve as their new independent capital, the situation entered an approximate stalemate for the next quarter-century. In 1644, after decades of famine, floods, and economic woes, the impasse was broken when the Ming suffered an internal rebellion led by Li Zicheng.
Capturing Beijing on April 24, 1644, the last Ming Emperor hung himself in the imperial garden and Zicheng proclaimed himself the Shun Emperor. However, in his efforts to solidify his fledgling regime Zicheng sought to purge the military ranks of Ming loyalists. One such general, Wu Sangui, consequently defected to the Qing cause and with their combined forces defeated the new dynasty at the Battle of Shanhai Pass. With no true opposition left, the Qing set about pacifying the remnants of Ming China, a task that would take another forty years to complete. Declaring a new dynasty in 1661, the Kangxi Emperor claimed the throne and, finally, in 1683, after decades of war, the Qing emerged triumphant.