Although very much separated on the eastern hemisphere, degradation of the Roman Empire and Han China came in similar waves; the results of the ruined civilizations, however, varied in impact of future civilization.
The decline and fall of a great of empire as the Roman would have to be a result of many strong tribulations. To start with, the spread of diseases such as smallpox vastly severed its numbers and even killed the emperor Marcus Aurelius. With a population of 60 million in 180 B.C. the Roman demographic was reduced by 25%. With a decreased populace, there became fewer defenders of the borders. Invasions increased in frequency, and war too took many Roman lives. In the Roman Empire, invasion was provided by Germanic tribes. Some craved bloodlust while others migrated after being invaded themselves by the Huns.
Han China, too, faced struggles that would eventually depose imperial rule. Epidemic disease came later to China than to Rome but still had the same negative impact on classical Chinese society. As in Rome, Han China’s population in 200 C.E. peaked at 60 million and fell to 45 million by 600 C.E. Though also invaded by Hun tribes, a more influential cause of the decline of Han China came from corruption in the government impacted all Chinese citizens. As emperors became weak in will and power, military generals drew more power. Peasants grew angry with taxes unpaid be corrupted officials, and in 184 C.E., a group known as the Yellow Turban rebellion confronted Han government.
Even after its fall, the Roman Empire maintained an influence over future civilizations. The western Roman Empire finally fell in 476 C.E. to a Germanic general named Odovacer. But unlike Han China, imperial rule would still continue in the eastern part would continue for another thousand years as the Byzantine Empire. Consequently, the Latin language became dead, preserved only in the writings of the Roman Catholic church. As a result Germanic tribes were able to govern regions such as Gaul, Spain, and Britain.
The remaining states of Han China after 220 C.E. entered a period similar, but less violent, to that of the Period of the Warring States. Though Roman traditions faded, Chinese culture would persist; nomads from the steppe regions became sinicized and helped kept traditions alive. Han China disintegrated into three regional kingdoms, the Wu, Wei, and Shu. Contrary to the Romans, China, after living in disorder for almost 350 years, would be unified under the Sui dynasty. Whereas Confucianism was a prominent philosophy in earlier Chinese dynasties, Mahayana Buddhism became a popular religion during the fourth to sixth centuries to accompany the new changes in power. In the end, the people of both regions localized trade and became self-sufficient.