The Battle of Shanhai Pass, fought on May 27, 1644 at Shanhai Pass at the eastern end of the Great Wall, was a decisive battle leading to the beginning of the Qing dynasty rule in China proper. There, the Qing prince-regent Dorgon allied with former Ming general Wu Sangui to defeat rebel leader Li Zicheng of the Shun dynasty, allowing Dorgon and the Qing army to rapidly conquer Beijing.

The Qing dynasty, officially the Great Qing, was a Manchu-led imperial dynasty of China and the last imperial dynasty in Chinese history. The dynasty, proclaimed in Shenyang in 1636, seized control of Beijing in 1644, which is considered the start of the dynasty's rule. The dynasty lasted until 1912, when it was overthrown in the Xinhai Revolution. In Chinese historiography, the Qing dynasty was preceded by the Ming dynasty and succeeded by the Republic of China. The multi-ethnic Qing dynasty assembled the territorial base for modern China. It was the largest imperial dynasty in the history of China and in 1790 the fourth-largest empire in world history in terms of territorial size. With over 426 million citizens in 1907, it was the most populous country in the world at the time.