The fertile fields south of Yinshan are not only the scope of nomads, but also the springboard for them to enter the Central Plains. As long as they occupy this fertile field, they will cross the Yellow River and enter the Fenhe River or the Yellow River Valley. If they lose this fertile field, they will lose the basis for survival. This is the reason why they did not stop crying after the Huns lost Yinshan. On the other hand, if the Han nationality wants to rule out the threat of nomads attacked from the northwest, they must also guard the entrance of the Yinshan, otherwise these riders will cross the Ordos Desert and enter the heart of Han residential areas.
passage?
The fertile fields south of Yinshan are extremely important to both the nomads and the Han nationality.