Emperor Wudi was the seventh emperor of the Han Dynasty of China. He ruled from 141 to 87 BC. During his reign, between about 130 and 110 BC, the Han ruling court and the army started winning major battles, and they conquered Xiongnu territory and greatly expanded the empire's territory in the north and west. At the same time, Han armies also defeated armies and navies to the south, and the empire expanded into what are now northern Vietnam, Yunnan, Guangxi and Guangdong. In this way, by about 100 BC, the size of the Han Empire was more than double what it was at the beginning. During the same time between 130 BC and 100 BC, trade with Western countries brought wealth to the rulers and merchants. Emperor Wudi’s court sent envoys to the west, and a large scale trade developed on the Silk Road routes involving large caravans that travelled between Changan that was the capital of the empire and the western countries. In this way, the Han's knowledge of the outside world, philosophy and religion, and technology increased. Technicians made advances in refining iron and making steel weapons and tools during and after his reign. So by the creation of wealth and territorial expansion and strength, the Han Empire initially prospered a lot, but at the end of his life he became despotic.
After the fall of the Qin Dynasty in 206 in a rebellion that was led by a peasant named Liu Bang, the Han Empire began. Liu Bang reigned as Emperor Gaozu of Han. He inherited the infrastructure construction of the Qin including roads, canals and the Great Wall, but the population of the whole region was impoverished. The population dropped down to an estimated 18 million due to the activity of the Qin court and rebellions. The Xiongnu threatened from the north, and Liu Bang had to give tribute to them. The first emperors of the Western Han Dynasty were hard-pressed by external threats and internal strife. Though Liu Bang had accepted the administration of kings in the eastern part of the empire, during his long illness before his death, he grew suspicious of some of his top leaders. He regarded them as rivals, and they were killed or demoted. After his death, the ruling clan succeeded in deposing the other kings and putting imperial family members in their places by about the year 155 BC. The imperial clan thereby consolidated their power over the empire.
Han Wudi (汉武帝, 156-87) inherited this newly established imperial power when he was 15. He was thought to be an effective governor. His campaigns usually succeeded in expanding the empire. The empire stretched to Central Asia, Korea and Vietnam. He kept the Xiongnu out and established Silk Road trade by sending Zhang Qian to the Yuezhi in 139 BC. He lived for 54 years, and during his long reign he consolidated power in the territory. This is one of the longest reigns in dynastic history.
Almost as soon as he started reigning, he presided over an examination of Confucian scholars, and the court put some of those who were successful in the exam in official positions. Then the ruling court started a Confucian academy. In this way, he presided over the establishment of the Confucian Imperial Examination to select people for governmental positions. Those who passed the examination were guaranteed to be literate and knowledgeable about Confucian political philosophy. This was the main way that people were selected for government in most of the big regional dynasties during the next 2,000 years.
In the year 119, he established the northern boundaries and made some peace with the roving Xiongnu by sending several armies against the Xiongnu's leading clans. Two generals named Wei and Huo made direct assaults on Chanyu Yizhixie's forces, destroyed his army, and nearly captured him. Then the Xiongnu wanted peace for a few years.
However, towards the end of the reign, he became corrupt. In response to a bad dream, he accused many people of witchcraft and had them killed. He tried to find magicians who would give him something to prolong his life. Also, he started installing despotic rulers who executed people for no reason. In order to stop any rebellion, he executed people who even criticized him. He started to overspend on palaces and tours and luxuries. To obtain money, the court decreed imperial monopolies on salt and iron. Salt was considered a necessary nutrient, so they could sell it at high prices. Iron was necessary for tools and weapons. He also started too many campaigns for conquest against the Koreans and the kingdoms in the south.
Starting about 100 BC, due to the heavy taxation and military campaigns, there were many peasant revolts throughout the empire. In trying to suppress the rebellions, he decreed that officials presiding over areas in which there were rebellions would be killed. The officials responded by trying to hide news of the revolts from him.
When he was old, his son revolted. It is said that he started a rebellion because some of the court officials hatched a plot against him that his father didn’t know about. It is said that Emperor Wudi was spending a lot of time with concubines instead of presiding as emperor. There was some fighting, and his son was killed by some officials. At the end of his life, he realized that his treatment of the people was too harsh and that he should stop his wars and allow the people to farm in peace without heavy taxation. He also realized that his son was plotted against and that his witchcraft inquisitions were wrong. He apologized to his empire about his past policy mistakes in a public edict known as the Repenting Edict of Luntai. He named Prince Fuling to be the next emperor and died in 87 BC. Crown Prince Fuling ruled under the title Emperor Zhao for the next 13 years.