What was the experience of building the Great Wall for the second time in Han Dynasty?

The second time was in BC 12 1 year. Emperor Wu of the Han Dynasty launched the battle of Hexi, and sent Huo Qubing, a general in title of generals in ancient times, to make a second surprise attack. He wiped out more than 40,000 Huns, received more than 40,000 defectors, defeated the right-wing forces of Xiongnu, and seized another strategic place-Hexi Corridor.

After that, Emperor Wu of the Han Dynasty still immigrated to set up a county and built a defense. In BC 12 1 year, he set up two counties, Wuwei and Jiuquan, and began to build a mausoleum in the east, that is, on the west bank of the Yellow River in Yongdeng County, Gansu Province, along the Hexi Corridor, and in the west to the "Lingjusai" Great Wall in Jinta County in the north of Jiuquan.

Regarding the repair of the Great Wall, Qian Chuan recorded: "The Han Dynasty began to build a residence in the west, and Jiuquan County was first set up to connect with the northwest."

There is also a related record in Zhang Hanqian Biography: "Lingju, named after the county, belongs to Jincheng. Zhusaixi to Jiuquan also. " This section of the Great Wall is the first section of the Hexi Great Wall in Han Dynasty, and it is also the second large-scale construction of the Great Wall in the period of Emperor Wu of Han Dynasty.