Compounding this political weakness and peasant unrest was the effect of several devastating epidemics that wiped out nearly half the population. The death of so many peasants diminished grain production and reduced the tax base for the government, just as the government needed resources to deal with the invading Huns. With all this internal turmoil, the weakened Han dynasty could not fend off the advance of the Hun invaders who easily crossed the abandoned Great Wall. The Han fell in 220 C.E. and China temporarily fell into a period of disunity.
The Han Empire fell because of political corruption by higher class citizens, resentment from the lower class, revolts from the Daoist Yellow Turbans, death from epidemics brought from trade, decrease in tax revenue and The Hun invasions