Reigned from 140 BC to 87 BC, Liu Che was known as Emperor Wudi of Han Dynasty. He had a great talent, bold vision, outstanding statecraft and brilliant military exploits, which made China enter into a time of great prosperity and one of the most powerful empires in the world.

Soon after Liu Bang founded Han Dynasty, he granted territories in stategic parts of the country to nobles of his clan, with the title of king. The kings had their own armies, levied their own taxes, issued currency, and appointed and removed officials within their own jurisdictions. When Emperor Wudi came to the throne, fearing that the kings were too powerful, he instituted a system whereby the descendants of the kings inherited parts of kingdoms as marquisates. Thus kingdoms quickly became divided into smaller and weaker territories, and came under the direct control of the imperial court. Later, Emperor Wudi went even further, depriving many nobles of their titles, and strengthening central rule.

It was during the reign of Emperor Wudi that the Confucian scholar Dong Zhongshu adapted Confucian theory to the needs of centralized politics. First, he stressed that Heaven dominated everthing in the world. The emperor was Heavenly son, and he ruled over poeple on behalf of Heaven. Therefore, all people, including kings, should abide by the will of the emperor, a concept which was called grand unification. Second, Dong Zhongshu advocated suppressing the hundred Schools of Thought and making Confucianism the state of ideology. This, he argued, would unify the people's minds, which in turn would consolidate political unity.

Emperor Wudi was impressed by Dong Zhongshu theories, and filled his administration with Confucian scholars. Confucianism thereby gained a foothold as the dominant ideology in Chinese feudal society.

Wudi enforced the central military power, set forth a central standing army. He also moved a large number of people to the northern border areas to open up wasteland, enforced the frontier fortress and strengthen the defense so that the empire military force was empowered. From 133 BC, under the lead of famous general Li Guang, Wei Qing and Huo Qubing, Han army attacked the frequently intruding Huns, and after three great battles, they achieved a decisive victory. He also endeavored an expedition toward the boundary and the hinterland of Asia, and expanded the territory of China.

Zhang Qian was sent on diplomatic missions twice by Wudi, connecting communication among the countries in the Western Regions and Han Dynasty. Zhang Qian reported his experiences to Wudi and mentioned the destination of Silk Road - the Roamn Empire.

With the increasing power, people of the Central Plains began to be called "Han people" or "Han nationality" instead of "Qin people". Wudi became the second great emperor who made great achievements to the country.