Domestic turmoil laid China open to attack, and in 1931 the Japanese occupied Manchuria, founding the puppet state of Manchukuo and placing the last Qing emperor, Pu Yi, at its head. By 1937 the Japanese had occupied much of northern China, Shanghai, and the Yangtze valley ruthlessly taking cities, wreaking death and devastation. The Japanese were finally driven from Chinese soil in 1945, and China was plunged into civil war.