How did Emperor Wu of the Han Dynasty develop the northwest frontier?

In the spring of the second year of Yuan Shuo (before 127), the Huns entered Shanggu and Yuyang, killing more than a thousand officials and civilians. Emperor Wu of the Han Dynasty sent generals Wei Qing and Li Xi to Gaoque, north of Shuofang, and R&F, west, and captured more than a thousand people. They won a great victory, recovered Henan in this Hetao area, and set up two counties, namely Shuofang and Wuyuan. In order to consolidate the rule in this area, we "recruited 100,000 immigrants" this summer.

(2) In the fourth year of Yuanshou (before 1 19), Shandong was flooded and the people were hungry. It is still not enough for Emperor Wu of the Han Dynasty to send messengers to allocate food in the county warehouse to help the victims. He also "raised wealth" and gave money and grain "fake loans" to the poor. If the poor could not be saved, he let the poor in Kanto migrate to Longxi, Beidi and Xihe. '

(3) In the fourth year of Yuanshou, Wei Qing and Huo Qubing attacked Xiongnu separately and defeated Xiongnu. From then on, the Huns fled far away, and there was no Wang Ting in the south of the desert. This year, the army has also made great progress in reclaiming farmland, from the west of Shuofang to Lingju (now northwest of Yongdeng, Gansu). "There are often 50,000 to 60,000 people in the canal, which is slightly eroded and leads to the north of Xiongnu." ：

(4) In the fifth year of Yuanshou (formerly 1 18), "officials and people moved to the world with cunning".

(5) In the fifth year of Ding Yuan (before 1 12), "Zhangye and Jiuquan counties, Shangxian, Shuofang, Xihe and Hexi opened official fields and expelled 600,000 people to keep the fields".

(6) In the sixth year of Ding Yuan (before 1 1 1), "Wuwei and Jiuquan were divided, and Zhangye and Dunhuang were established, which was taken as a fact by immigrants".

The above six records, except for the scale, region and number of people in the northwest frontier counties recorded in Articles 3 and 5, the other four records are all records of direct immigration. How many people moved to the border these four times? The exact number is unknown, but there are at least about one million people. After these people were moved to the northwest frontier county, the government provided basic means of production. Emperor Wu of the Han Dynasty developed the counties in the northwest frontier and practiced the policy of reclaiming wasteland, which had a great influence on China's later generations. During the Three Kingdoms period, Cao Cao said in the Preface to Setting Fields: "Filial piety is a good example for ancestors to set the western regions by plowing fields." Cao Cao's reclamation in Xuchang and other places was carried out on the basis of summing up the reclamation of northwest border counties by Emperor Wu of Han Dynasty. Therefore, it should be said that the large-scale reclamation of farmland by Emperor Wu of the Han Dynasty in the northwest frontier county benefited future generations at that time.