Qin dynasty 's rulership became one of the most flourishing years of China . As commented by Hoai Do : ``The Han Dynasty (206 B .C . - A .D . 220 ) created such an impression on China that even today the Chinese refer themselves as "Men of Han . The Han Empire stretched from the Pamir Mountains (Afghanistan ) in the west to Korea in the east and from Mongolia in the north to Vietnam in the south . Major achievements during this dynasty included the...