It is easier to attack a city than to defend it. On the management of Hexi Corridor by Emperor Wu of Han Dynasty.

Hexi Corridor, a well-known name in the history of China, is the traffic artery controlled by dynasties. It starts from Wushaoling in the east, reaches Yumenguan in the west, abuts Qilian Mountain in the south and Helishan Mountain in the north, with a total length of about 1000 km. Aquatic plants are abundant and the environment is suitable. It is the throat artery leading to the western regions in the east of China and an important frontier defense place in the northwest. During the Spring and Autumn Period of the Eastern Zhou Dynasty, it was occupied by Xirong, during the Warring States Period and before the Qin Dynasty, it was occupied by Yue people, until the fourth year of Emperor Wendi (BC 176), and Hexi area was finally occupied by Xiongnu. Occupying this fertile soil of aquatic plants, the expanding Xiongnu directly threatened the rule of the Han Dynasty. After more than 70 years of development in Gaozu, Hui Di and Wenjing dynasties, the national strength of the Western Han Dynasty was greatly enhanced in the period of Emperor Wu of Han Dynasty, and it basically possessed the ability to wrestle with Xiongnu. In the third year of Yuanshuo (BC 126), Zhang Qian, who was ordered to send an envoy to the western regions, returned to Chang 'an, bringing back a lot of information about Xiongnu. After listening to Zhang Qian's report, Emperor Wu of the Han Dynasty decided to crusade against Xiongnu and seize Hexi region. In the spring and summer of the second year of Yuanshou, Emperor Wu of the Han Dynasty sent Huo Qubing, a general of generals in ancient times, out of Longyou to levy the Xiongnu, defeated the evil king of Xiongnu who occupied the Hexi Corridor, and annihilated the enemy by 40,000. The evil king of Xiongnu was forced to land in the Han Dynasty, and Hexi area was finally incorporated into the territory of the Han Dynasty. Huo Qubing's campaign in the Hexi Corridor of Xiongnu lies in the east-west communication artery between the Central Plains and western countries, and is also the core area of the Sino-Hungarian War. Therefore, the Han Dynasty attached great importance to the management of this area, especially after two years of Yuanshou, the Hexi Corridor was completely incorporated into the territory of the Han Dynasty, and the Han Dynasty took measures from political, economic, military and other aspects to start a large-scale and all-round management of this area. In order to strengthen the defense forces in the border areas and adjust measures to local conditions, Guan Saihan built the Hexi frontier fortress in stages in about 30 years according to the topography of the Hexi Corridor. As one of the important measures to control the northwest in the Han Dynasty, the construction of these border blockade lines played a certain role in strengthening the border defense forces in the Han Dynasty. The construction of the Hexi frontier fortress of Juyansai site began in Yu Ling, which lasted for six years in Ding Yuan (before11), and "tens of thousands of people crossed the river to build tombs". Even though Li Xi and Xu Zi built forts in Lingzhou and stationed troops to prevent accidents, in order to achieve the strategic goal of facilitating contact with the western regions and avoiding the combination of Hungary and Qiang, border blockade lines were built from Lingzhou to Jiuquan and Jiuquan to Yumen. In the second year of Tai Chu (102 years ago), Juyanze, which was built by captain Lu Bode with a strong crossbow, also played an important role in maintaining the safety of Zhangye and Jiuquan counties and the smooth traffic roads leading to the western regions. Cities, barriers, pavilions, tunnels and other facilities were also built along the Han border, which together formed a relatively complete defense system and became one of the main defense tools for Hexi border defense in Han Dynasty. ""At the beginning of Hexi, four counties were set up, with Yumen as the gateway, which isolated Hu Xian and prevented the north and south from crossing the border, so the barrier pavilion was thousands of miles away from the Great Wall. In addition to building border blockades, the Han Dynasty also set up "customs" as guard places in relatively dangerous places or border areas. The Han Dynasty set up four passes in Hexi Corridor, namely Yumenguan Pass, Yangguan Pass, Jinguan Pass and Hangsuo Pass. Among them, Yumenguan and Yangguan, located in Longle County, Dunhuang County, were the places ruled by Dewey, and they were the throat areas of communication between the Central Plains Dynasty and the western regions at that time. Jinguan and Hangsuoguan are located on the Heihe River line in the middle of Hexi Corridor to guard some valley passes between the Corridor and Inner Mongolia Plateau. After the establishment of four counties in Hexi in Yumenguan and Yangguan and the return of Hexi Corridor to Han, in order to strengthen the rule of this area, strengthen its defense forces in the northwest border, better crack down on Xiongnu and communicate with the western regions, isolate Xiongnu from the countries in the south of the corridor and jointly resist Han, and at the same time take border defense measures such as building barriers, Han began to set up administrative institutions such as counties and counties in this area one after another, and sent officials to handle related civil affairs and border defense affairs. In view of the complex terrain, numerous ethnic minorities and important military traffic position in Hexi Corridor, the system of parallel counties subordinate to the state was implemented according to local conditions. This complete administrative system played an extremely important role in strengthening the management of Hexi Corridor in the Han Dynasty and even improving the border defense forces of the whole northwest region. Four Counties in Hexi Han gradually set up four counties in Hexi Corridor, starting from Jiuquan County. With the escalation of the Sino-Hungarian War, the Han Dynasty urgently needed to strengthen the military defense capability and administrative management in this area. It is precisely to meet the needs of this change in the military and political situation that Jiuquan County was separated from the other three counties. Therefore, it shows that the control of Hexi Corridor in Han Dynasty was gradually refined. On the other hand, due to the effective management of Hexi region, the Han Dynasty's attack on Xiongnu was politically guaranteed and promoted, so it can be said that the two are complementary. For example, the location of counties and counties is generally near rivers, giving full consideration to the natural conditions of dry climate and water shortage and the needs of military struggle. This complete administrative system also played an important role in strengthening the defense forces in Hexi and realizing the strategic intention of connecting the western regions and isolating Qiang and Hu. It is of great and far-reaching historical significance for the Han Dynasty to set up four counties in Hexi. Since then, Hexi Corridor has really become a strategic place to "break the right arm of Xiongnu", which has strengthened the defensive ability of the Han Dynasty in the northwest border. It also created the possibility for western countries and the Han Dynasty to jointly fight against the Huns, laid the foundation for ensuring the smooth flow of the Silk Road, and thus promoted the economic and cultural exchanges between western civilization and China society. During the Western Han Dynasty, the four counties in Hexi Corridor not only set up counties in Hexi Corridor to strengthen management and rule, but also set up dependent countries according to local conditions, mainly to resettle a few tribes who surrendered to the Han Dynasty in the war. The bureaucracy of a vassal state usually consists of two parts, namely, the captain, minister, Hou or Sima of the vassal state. The original thousands of miles, hundreds of miles and canals of ethnic minorities constitute the vassal States in the lower Hexi area. Historical records show that Zhang Wei, Zhang Wei Juyan and Jiuquan are more common. " If you don't change your own customs, you belong to the Han Dynasty, so you belong to the country. "-The parallel implementation of the county system and the county system in Hanshu in Hexi area effectively strengthened the Han Dynasty's rule over Hexi Corridor and basically ensured the stability and security of the northwest frontier. It also played an important role in the further and better governance of the western regions in the Han Dynasty and ultimately defeated the Xiongnu. After the Western Han Dynasty captured the Hexi Corridor, it also implemented measures such as resettlement of immigrants and development of wasteland to consolidate the material foundation of this area economically. This is not only conducive to the political stability in Hexi region, but also lays a good economic foundation for further operating the western regions and attacking Xiongnu. The Han dynasty carried out many immigration policies in Hexi area, which greatly increased the local population, brought advanced production tools and agricultural technology from the mainland, promoted the agricultural development in the border areas, changed the desolate and backward face of Hexi, and provided sufficient rations for the soldiers guarding the border. These immigrants should not only carry out normal agricultural and animal husbandry production, but also "guard the frontier, treat them with two thousand stones, and serve the army and horses", so they also played a great role in consolidating the northwest frontier defense. ""Later (in the second year of Yuanshou), General Park Qi smashed the right land of Xiongnu, reduced evil spirits, stopped the slaughter of Wang, cleared the land, and began to build imperial houses to the west, initially setting up Jiuquan County. Later, because immigrants were a little richer. " -"Hanshu" Yuan Shou four years (before 1 19) After the Battle of Mobei, the Xiongnu failed during the Yuanfeng period of Emperor Wu of the Han Dynasty. "Khan benefited the northwest, stayed in the clouds, and left Jiuquan and Dunhuang counties on the right" in an attempt to control the western regions. In view of the change of this situation, Emperor Wu of the Han Dynasty was determined to vigorously develop Hexi region, and on the basis of consolidating his strong rule over Hexi Corridor, he further launched a war with Xiongnu for the western regions, so he began to reclaim land in Hexi region. Hexi farming sites are mainly distributed in Lingju, Fanhe, Wuwei, Juyan, Jiuquan and Dunhuang, and the largest is Juyan farming area. Due to the large-scale reclamation in Juyan area, it has played a very important role in consolidating border defense. Therefore, in order to strengthen the effective management of Juyan reclamation, Han * * * also set up a captain of Juyan Agriculture, and the officials of Juyan and Matian are within the jurisdiction of the captain of Juyan Agriculture. ""The Vietnamese people lost 0/80,000 troops in Jiuquan and Zhangye, settled in Juyan, and stayed in Jiuquan "-Historical Records Juyan wasteland development can be carried out smoothly because there is a relatively complete organization and management system as a guarantee. Dunhuang, located at the westernmost end of Hexi Corridor, is the throat of communication between China and the West. There are also some wasteland sites here. Hexi farming sites are all over Hexi Corridor, with large scale and long duration. Years of land reclamation and development have greatly increased the grain output in Hexi, which not only ensured the prosperity of people's lives, but also provided a solid economic foundation for the Han Dynasty to fight against Xiongnu. It is precisely because of the long-term implementation of land reclamation and development that the defense forces of counties in Hexi border area have been strengthened, and the invasion and plunder of Hexi border area by Huns have been alleviated to some extent. In the second year of Yuanshou, the Han Dynasty finally won two battles in Hexi Corridor, which made the Han Dynasty get rid of the unfavorable situation of the Sino-Hungarian War and took the initiative. Therefore, it can be used as a base for garrisoning or leaving the army, and the Xiongnu can be completely eliminated in a larger scope. It can even be said that the victory of Hexi War was an important opportunity for the rise of the Han Dynasty. It was precisely because the Han Dynasty seized the strategic location of the Hexi Corridor that the final result of the Sino-Hungarian War was predicted to some extent.