If we say that Qin Shihuang was the first emperor who unified China in terms of territory, then the first emperor who unified China in terms of ideology was none other than Han Wudi (Emperor Wu of the Western Han Dynasty). In order to consolidate his rule, he proscribed all non-Confucian schools of thought and espoused Confucianism as the state ideology, thus pushing Confucius up into the orthodox position. For two thousand years thereafter, Confucianism had been the only one dominant school of thought in China.
Han Wudi, named Liuche, ascended the throne at the age of 15. He was the fifth emperor of the Western Han Dynasty (206BC-8AD) and reigned from 141BC to 86BC, which is one of the most celebrated periods in Chinese history. During the period of Wen and Jing emperors before Han Wudi, China was peaceful and prosperous -- population grew greatly and industry and commerce were developed. Han Wudi, son of Emperor Jin, carried out a series of reforms and devoted himself to military conquests and territorial expansion.
Han Wudi's most important military campaigns were against the Hun, an ancient tribe that lived in North China who posed a powerful threat to the Han Empire. After three expeditions, Han Wudi finally drove the Hun into the far north of Gobi, thus maintaining the safety of the Hexi Corridor. In order to avoid the aggression of other nomadic tribes, Han Wudi also ordered the construction of the Great Wall.
In 138 BC, Han Wudi sent Zhang Qian -- Chinese ambassador-- with a diplomatic expedition to Central Asia to try to find allies against the Hun. Failing to achieve his original purpose, Chinese ruler became aware of the cultures and customs of other nationalities. Eventually, this led to the opening of the Silk Road, which later served as a route for cultural and economic exchange between the east and the west.
Han Wudi accepted Dong Zhongru's proposal of "rejecting the other schools of thought and respecting only Confucianism" which ended the period of "contention among one hundred schools of thought". Afterwards, Confucian thought became gradually an orthodox theory and had a far-reaching influence on Chinese philosophy. He also restrained other thoughts but made Confucianism a state ideology. While unifying the state ideology, Han Wudi strengthened the centralized state power and weakened local forces.
He realized the malpractice of eupatrid and established the Imperial College to train qualified officials and talents to strengthen feudal centralization. Han Wudi was not only a statesman but also of great talent. "Yuefu" -- an official conservatory was set up to collect folk songs and ballads and most of the folk songs in the Han Dynasty were come down from that period. Yuefu poems had a great influence on later periods.
In order to pay his military cost, Han Wudi raised taxes, nationalized many private businesses and confiscated property of the nobility. He also advocated statism in the fields of finance and commerce. For example, he announced that only the coins minted by the central government could be in circulation; metallurgy and salt processing were also forbidden among the people. Business run by the government enjoyed an exclusive right and the government imposed heavy property tax on industrialists and businessmen to enhance the income of the court. The Western Han Dynasty became unprecedented rich and powerful, centralization strengthened and its feudal economy flourished.
During the reign of Han Wudi, the Western Han Dynasty was in a period of great prosperity. Han Wudi died at the age of 71 in 86BC. The Western Han began to decline after his death. Wudi was buried in Maoling in Xian Yang of today's Shaanxi Province. His tomb was a subulate in shape. The tomb covers 54,054 square meters. On the remains of the bounding walls, the vestiges of watchtowers could be seen. The largest among the tombs of the Western Han Dynasty, with richest funeral objects, the tomb is named Pyramid in China.