Since the establishment of the Song Dynasty, Taizu Zhao Kuangyin had the ambition to recover the lost land of Yanyun, but unfortunately Taizu went early before he could realize it. After that, Emperor Taizong also wanted to use the means of war to retake Youyun Sixteen Prefectures, but he fought several times in a row with Daliao, and he was defeated. Successive wars caused the Song Dynasty to suffer heavy losses and huge economic consumption, and finally Emperor Taizong had to abandon his plan to recover Youyun Sixteen Prefectures. However, the subsequent Song Dynasty still remembered this place and wanted to recover it many times. So where is the Sixteen Prefectures of Youyun, and why did the Song Dynasty have such a deep obsession with this place?
Unfortunately, before the Song Dynasty, the Central Plains lost this important treasure land, and this place has always been in the hands of the Khitans. Why is such an important place in the hands of the Khitans?
This dates back to the Later Tang Dynasty, when the political situation was very chaotic, and the chancellor Shi Jingyao rebelled and wanted to overthrow the regime at that time and become emperor himself. However, his strength was far from enough to support him to win the war, so when he was besieged by the Tang army in Taiyuan and in a dilemma, he thought of a surprising decision, that is, to ask the Liao army for help, that is, the Khitan clan, and he wanted to use the Khitan army to fight against the Tang army and realize his dream. At that time, the Khitan also readily agreed to Shi Jingyao, and then went all the way south to defeat the Tang army and achieve the final victory. After the victory, with the support of the Khitans, Shi Jingyao smoothly became the emperor of the Great Jin Dynasty. But the Khitan will not help you for no reason, and in the end you will definitely have to pay the same value or even pay a greater price in return, and Shi Jingyao at that time was completely dependent on the Khitan to successfully take the throne, in a sense, equivalent to a puppet set up by the Khitan in the Central Plains. So in the end, Shi Jingyao gave way to Heshan and ceded such an important geographical defense line to the Khitans. The cession of Youyun Sixteen Prefectures also opened the gateway of the Central Plains in the north to the nomads. Since then, this place has become a heart disease for many people in power, and it is difficult to sit back and relax without recovering it.
In addition to its important strategic defensive function, the Song Dynasty has always wanted to take back this part of the territory, probably in part because it is the territory of the Central Plains, and the people living in these areas are also the people of the Central Plains. It was originally surrendered, but it has not been taken back so far, which is also a very humiliating thing for the Central Plains Dynasty. Therefore, many emperors regarded the recovery of Youyun as a major responsibility and task of their reign, and also wanted to prove their political talents and consolidate their position by liberating the Youyun region. During the reign of Song Taizu, he once said, "The Yan and Jin dynasties have not been restored, but it can be said that the unification is too peaceful." The Yanjin region referred to here is roughly equivalent to the area west of the Taihang Mountains and east of the Taihang Mountains. To put this sentence bluntly, the land has not been lost, and some people are still living under the rule of foreigners, how can it be regarded as the unification of the world? Therefore, for the Central Plains Dynasty, it was necessary to recover the clouds.
In addition to national defense, territorial ownership, the third important reason is the economic aspect. There are not many geographical areas in Youyun Sixteen Prefectures, and a year's tax is a considerable amount of income, so including Youzhou in the territory of the Central Plains can add a huge fiscal revenue to the central government. In addition, Youzhou's geographical location is superior, and the humid climate is very suitable for the development of agriculture and animal husbandry. Therefore, agriculture in this region has always been very developed, and the economy has been prosperous. If one day there is a conflict between the Central Plains and the nomadic peoples in the north, to the point of fighting each other, Youzhou can also provide sufficient grain and grass for the army, and can also help the Central Plains share a part of the military expenditure. Because Youzhou has always been at the junction of the Central Plains and nomadic peoples, one of their long history and culture is horse breeding culture, coupled with the developed animal husbandry, so that their horse breeding technology is superior to other regions, and the war horses they have bred are more endurance and explosive than other areas. This resource was very important to the Northern Song Dynasty, which was conducive to them forming their own cavalry team!
Therefore, the Youyun area can not only resist the invasion of foreigners in the north, but also become an important reliance on the Central Plains to provide major economic support for the Central Plains, that is, because of these three important functions, youyun Sixteen Prefectures have become the areas that the Song Dynasty has always wanted to recover! But unfortunately, Youyun Sixteen Prefectures were not successfully taken back by the Central Plains during the Song Dynasty, and the demise of the Song Dynasty was inextricably linked to the fact that Youyun was in the hands of the northern nomads!