because in thoes times they had a great influence in asia, they was notice as the powerhouse of asia, and asians look up to china at that time economically,culturally and military but im not sure about military wise though since they got thier buts kicked by the koreans in koga. another reason is government were run by scholars and many inventions took place like flame throwers and catapults and weapond use with gun powder from firecrackers. another reason could be perhaps they been invaded by so many time by outsiders and lost the northern part of china because they had good goverment and but weak army.
