Battle of Shanhai Pass
1644 CE.
Shown on the map at 39.979°, 119.776°.
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 peasant rebel leader Li Zicheng, founder of the short-lived Shun dynasty, allowing Dorgon and the Qing army to rapidly conquer Beijing.
Text from the Wikipedia article Battle of Shanhai Pass, licensed CC BY-SA 4.0.