What contribution did Emperor Wu of the Han Dynasty make in governing the frontier?

Emperor Wu of the Han Dynasty sent troops to crusade against the Huns, which made the regime of the Western Han Dynasty more consolidated and the country more unified, and created extremely favorable conditions for the economic and cultural development of the Western Han Dynasty. From 133 BC to 1 19 BC, Emperor Wu of the Han Dynasty sent troops to carry out many large-scale battles with the Xiongnu, and finally won an all-round victory over the Xiongnu, which fully reflected his great talent and excellent military command ability. In the process of fighting against Xiongnu, Emperor Wu of the Han Dynasty also enriched the frontier defense and developed production through a large number of immigrants.

Emperor Wu of the Han Dynasty sent Zhang Qian to the Western Regions twice, which strengthened the economic and cultural exchanges between the Han Dynasty and the West. In BC 138, Zhang Qian, a famous and great explorer in the history of China, was ordered by Emperor Wu of the Han Dynasty to go to the Western Regions, with the purpose of uniting with the Dayue family to defend and attack the Xiongnu forces. In BC 1 19, Zhang Qian was ordered to go to the Western Regions for the second time. Subsequently, countries in Central Asia and the Western Regions often visited and traded in Chang 'an in the name of tribute. The exchange of personnel and trade between China and other countries in the western regions lasted for more than 1000 years, starting from the Western Han Dynasty, passing through the Eastern Han Dynasty, the Wei, Jin, Southern and Northern Dynasties and finally the Tang Dynasty.

Emperor Wu of the Han Dynasty opened up the southern and southwestern territories, which made the Yue nationality, southwest ethnic minorities and Han nationality better integrated. After Emperor Wu of the Han Dynasty assigned the three tribes of the Yue nationality to the Han Dynasty, they moved to the Yangtze River, Huaihe River, South China Sea and other places, and lived together with the Han nationality for a long time, and gradually merged with each other, forming a "great unification" situation that has not been completed since the pre-Qin period. In the process of developing southwest China, Emperor Wu of the Han Dynasty spread iron tools and high Han culture to these areas, which more or less broke the occlusion of these areas and promoted the development of local economy and culture.