fifth century A.D. India was afflicted by the Ephthalites or White Huns, who levied tribute on the small Indian princes and held India in terror. Every summer these Ephthalites pastured in western Turkestan, every autumn they came down through the passes to terrorize India.
In the second century A.D. a great misfortune came upon the Roman and Chinese empires that probably weakened the resistance of both to barbarian pressure. This was a pestilence of unexampled virulence. It raged for eleven years in China and disorganized the social framework profoundly. The Han dynasty fell, and a new age of division and confusion began from which China did not fairly recover until the seventh century A.D. with the coming of the great Tang dynasty.