The decline of the Ming Dynasty created a good chance for the Nuzhen people (i.e. Manchu). In the late Ming Dynasty (1368-1643), the imperial government became very corrupt. Government officials preyed peasants' farmland; the emperors were fatuous; eunuchs in league with some government officials wielded enormous power. The politics was corrupt;the economy was fragile. However, during this period, the Nuzhen People who lived in Heilongjiang (northeast of China) became more and more powerful. They defeated the army of Ming dynasty and became the rulers of China.

They overthrew the Ming and expanded outward.