In the Han Dynasty's battle against Xiongnu, which battles were used to determine the boundary between Xiongnu and Han Dynasty?

* * * twice. The first time was 127 BC. Wei Qing led the Han army from Yunzhong County, which is now Tuoketuo County, Inner Mongolia, all the way along the Yellow River to the west, to Gaoque plug, which is now Yinshan Jilan Pass, and then all the way south to Longxi County, which is now Tianshui, Gansu Province, to expel the Xiongnu forces in the Hetao area and drive away the Xiongnu Aries King.

North Korea has two counties, Shuofang and Wuyuan!

The second battle was divided into two stages. The first stage was in the spring of 12 1 year BC. Huo Qubing led ten thousand Han troops from Longxi county, swept the Hexi corridor to the west, and arrived in Shandan county of Zhangye city today, defeating the Xiongnu army in Hexi! The second stage is this summer. Huo Qubing once again took the lead, led the Han army from Beidi County, which is today's Qingyang City, Gansu Province, crossed the Tengger Desert and Badain Jaran Desert of the Yellow River, led the army to attack Juyanze, which is now Ejina Banner in Inner Mongolia, and then attacked Jiuquan City today along the weak water, defeating the Xiongnu in the decisive battle with the Xiongnu king to repair the map and the Xiongnu evil king Yanzhishan! Later, the evil king of Xiongnu feared the military strength of the Han army and led the Xiongnu tribe in Hexi Corridor to surrender to the Han Dynasty. Emperor Wu of the Han Dynasty moved them to five border counties in northern Han Dynasty, and set up four counties in the original Xiongnu area in Hexi and Dunhuang in Jiuquan, Wuwei, and moved the Han people to the border to immigrate there. Since then, the Hexi Corridor, which is more than 2,000 miles long, has been incorporated into the territory of the Han Dynasty, west of Lanzhou, Gansu!

These two battles decided the boundary division between Han Dynasty and Xiongnu!