In the Western Han Dynasty, the west of Yangguan and Yumenguan, which is today's Xinjiang and beyond, was called the Western Regions. From the beginning of Emperor Wu of the Han Dynasty, China began to communicate with the Western Regions, which were originally 36 countries, but later split into more than 50 countries, all located in the west of Xiongnu and south of Wusun. At the beginning of the Western Han Dynasty, the passage connecting East and West was blocked by Xiongnu. During the period of Emperor Wu of the Han Dynasty, the management of the western regions began to be strengthened.
When Emperor Wu of the Han Dynasty heard that the Yue family who moved westward had the intention of revenge against the Xiongnu, he sent someone to contact them to attack the Xiongnu. Zhang Qian, a native of Hanzhong, was recruited by Lang. In the second year of Jianyuan (BC 139), Zhang Qian led 100 people to the Western Regions. On the way, he was captured by Xiongnu, stayed for 10 years, finally managed to escape, and arrived at Dawan in the west dozens of days later. At this time, the Yue family had moved westward and did not want to attack the Huns. Zhang Qian didn't achieve his goal. He stayed in the Western Regions for more than a year, but was detained by the Huns for more than a year. After that, it coincided with the death of Hun Khan and the chaos in China. Three years later, Zhang Qian took the opportunity to return to Dahan and was warmly received by Emperor Wu of the Han Dynasty. Later, he was named Doctor Taizhong. Journey to the West lasted 10 years. Although it didn't achieve its goal, it got a lot of information about the western regions. Sima Qian called Zhang Qian's behavior "hollowing out".
After Zhang Qian returned to China, Emperor Wu of the Han Dynasty sent envoys to explore a communication line without going through the Xiongnu in the summer, but without success. Later, the Han army defeated the Huns, gained the Hexi Corridor, and opened the passage between the Western Han Dynasty and the Western Regions. After Huo Qubing defeated Xiongnu in Qilian Mountain, Zhang Qian suggested contacting Wusun, a powerful country in the western regions, to break Xiongnu's right arm. In the fourth year of Yuanshou, Zhang Qian went to the Western Regions again, with the purpose of attracting Wu Sun back to his hometown in Hexi and contacting other countries in the Western Regions.
Zhang Qian arrived in Wusun, but failed to achieve his goal. In 1 15 BC, he returned to Chang 'an with Wu Sun's envoys, and the envoys sent by Zhang Qian to other countries in the Western Regions also returned home one after another. Wu Sun's emissary saw the big fellow with deep pockets. After returning to China, Wu Sun gradually became close to the big fellow. In the following years, Zhang Qian went to Summer. From then on, the Western Han Dynasty began to have frequent contacts with northwest countries, and Zhang Qian hollowed out the western regions, which was later called the "Prince of Bo".
However, the western countries did not completely get rid of the control of Xiongnu. Under the instigation of Xiongnu, Loulan, Cheshi and other countries often plundered the envoys and caravans sent by the Western Han Dynasty to the Western Regions. In order to ensure the access to the western regions, in Yuanfeng three years, Wang Ju led the troops to break Loulan, and Zhao Ponu led the troops to break the car. In the sixth year of Yuanfeng, the Western Han Dynasty kissed King Wusun in an attempt to jointly force the Huns. At the same time, Emperor Wu of the Han Dynasty sent Li Guangli to attack Dawan (now Uzbekistan) for many times in order to break the Xiongnu's control over Dawan and gain its bloody horse. After paying a heavy price. The attack on the capital of Dawan greatly enhanced the prestige of the Western Han Dynasty in the western regions and ensured the traffic safety in the western regions. The "Silk Road" leading to the western regions has been unblocked.