What is the "Water Great Wall", the ultimate weapon to resist the Khitan fighters in the Northern Song Dynasty?

Sixteen States were captured in the early Song Dynasty, which made the Song Dynasty lose a very important defensive barrier, while the Liao State of Qidan occupied an excellent geographical advantage that could be attacked and defended.

This made the courtiers of Song Dynasty very worried, even though they had signed a contract with Liao? Yuan Geng League? But can national security only depend on a piece of paper? Therefore, the Northern Song Dynasty imperial court built many defense projects in eastern Hebei without natural barriers, the most noteworthy of which was? Water Great Wall? This kind of defense project based on water.

In ancient dynasties, resisting the invasion of nomadic people beyond the Great Wall has always been an important event of the country. However, in the early Northern Song Dynasty, due to the failure of the war, the natural protective barrier of the Central Plains was lost? Sixteen counties? The whole national defense border is like this? Bare? Exposed to the sight of the Khitan soldiers. This must be very unsafe. Therefore, a Hebei garrison commander named He proposed that more than 30 depressions should be connected by several rivers along the Hebei border to form a water defense line covering more than 450 kilometers, and then ditches should be continuously dug on this basis to form a connected water network between them, just like a river? Water Great Wall? Just so-so

Although? Water Great Wall? It was strongly supported by Song Taizong, but at the beginning of its construction, it did not show its effectiveness. In the second year of construction, Liao army invaded the Song Dynasty three times, which brought disaster to the border people. After that, He Chengju suggested continuing to dig the west, so? Water Great Wall? All the way to Xishan, blocking the southward passage of Liao army.

At this point, during the Northern Song Dynasty, Xitangbo in the west and Haikou in Gu Ni in the east stretched for thousands of miles, and 19 rivers converged, spanning seven military states. Water Great Wall? . For the Liao army, which is not good at water warfare, the Great Wall of Water? Have a good defensive ability. Since then, even if the nomads from the army and the Mongols went south, what about the Great Wall? It also played a very good role in limiting.