Battle of Shanhai Pass

The Battle of Shanhai Pass was the pivotal moment that allowed the Manchu Qing Dynasty to enter China proper. Ming general Wu Sangui, trapped between the rebel army of Li Zicheng that had captured Beijing and the Manchu forces outside the Great Wall, chose to open the gates to the Manchus. The combined Manchu and Ming forces routed Li Zicheng's rebel army, but the Manchus never left, establishing the Qing Dynasty that would rule China for nearly three centuries.