Excerpts from Books and Wikipedia
"The Later, or Eastern Han (25-220 CE) made their capital at Luoyang, during which Buddhism was introduced, and extended their domains into Central Asia;" [DK Timelines, p. 538] "With the end of the Han dynasty in 220, China plunged into a period of disunity and discord that might be compared to what is sometimes called Europe's Dark Ages, in which central control was lost. . . . For three centuries China experienced civil strife." [National Geographic Almanac, p. 118] "Within Chinese history, the most interesting parallel sequence of phases centers about the Han (206 BC-AD 220) and the Tang (618-907). . . . Each phase of imperial greatness was inaugurated by a short-lived powerful dynasty which unified the state, the Qin (221-206 BC) and the Sui (AD 589-618). Both the Han and the Tang, once established as a new unity, achieved an expansion of Chinese political power in neighboring regions, especially Central Asia, and a corresponding growth of foreign contact." [Fairbank: China, p. 46-8] [Note: Three dynasties coincided with divine revelation: Eastern Zhou with Buddha, Han with Jesus, and Tang with Muhammad.]