After the establishment of the Song Dynasty, the whole of China was still in a state of five dynasties and ten kingdoms. As the most powerful ruler of the separatist regime at that time, Zhao Kuangyin launched a war to unify the whole country shortly after he ascended the throne. After more than ten years of north-south campaigns, the Song Dynasty successively pacified the separatist regimes of Jingnan, Wuping, Houshu, Nanhan and Nantang, and unified most of the Central Plains.
During the national campaign, Zhao Kuangyin collected a large number of gold, silver, jewelry and silks and satins from the rulers of separatist regimes all over the country. Under normal circumstances, these collected wealth should be incorporated into the state treasury and become a part of state-owned assets, and then arranged by the financial management institutions of the imperial court as a whole. However, Zhao Kuangyin did not take this approach. Instead, he ordered all the wealth to be collected in the palace and set up a warehouse called the sealed pile warehouse. The question is, what is the intention of setting up another "small treasury" in Zhao Kuangyin? In fact, he has another account in his mind.
In 938, Shi Jingtang, the "son emperor" of the late Jin Dynasty, gave the Khitan sixteen states, which were located in today's Beijing, Tianjin, north of Haihe River, Hebei and north of Shanxi, in order to win the support of the Khitan. This is the famous "Sixteen States" in history. The geographical feature here is high in the north and low in the south. As long as it occupies the "Sixteen States", the north has formed a condescending situation towards the Central Plains. Therefore, "Sixteen States" has always been a battleground for military strategists, and its strategic position is extremely important.
After more than ten years of fighting in the south and the north, the Song Dynasty was very close to the goal of reunifying the whole country. The only remaining separatist forces are wuyue who obeyed the Song Dynasty and the dying Northern Han Dynasty. It was only a matter of time before these two regimes were incorporated into the territory of the Song Dynasty. The only suspense is the "Sixteen States" still in the hands of the Khitan. If this place is not recovered, then in a strict sense, the Song Dynasty is not a truly unified dynasty. Therefore, even if the strategic reasons are excluded, it is imperative for the Central Plains Dynasty to recover the "sixteen states".
At that time, the Liao regime established by the Khitan was powerful, and trying to recapture the "Sixteen States" from them was tantamount to grabbing food from the tiger's mouth. If you want to take it back by force, you will inevitably have a protracted war with Liao, and you may not be able to win. Therefore, the purpose of Zhao Kuangyin's setting up a pile bank is to redeem the "Sixteen States" in the hands of the Khitan with this amazing wealth. So what can be solved with money, why use a knife and gun to solve it? In order to show his determination, Zhao Kuangyin also released malicious words, saying that if the Khitan was in trouble, he would take the gold, silver and jewels in the pile-sealed library as the military assets of the Song Dynasty and recruit warriors from all over the world to seize them by force.
So, will the Khitans accept Zhao Kuangyin's generous terms? The answer is unknown, but it is easy to guess. This must be a flat refusal. Since ancient times, the territorial issue has been the core issue of a country, and it cannot be solved by spending money at all. If the rulers of Liao gave the strategic "Sixteen States" to Song Dynasty out of greed, the people of Liao could drown it with saliva. Besides, the regime established by Liao people as nomadic people has always been ruled by the strong. If the ruler is a soft-hearted man who sells land for glory, then his throne can be saved. Therefore, no matter how much money is paid here in the Song Dynasty, it is absolutely impossible to redeem the "Sixteen States" with the money from the pile library.
In addition, after the unification of China, the dynasties all relied on military strength to expand their territory, but now they want to redeem the homeland of the Central Plains with money, which really hurts the face of the dynasty and makes people feel ashamed. Therefore, except Song Taizong, the emperors of the Song Dynasty lacked ambition. Of course, this is not a compliment to Song Taizong. In fact, this man is ambitious but not talented, and the best army he can fight in the Song Dynasty is in his hands. The reason why the Song Dynasty was called "weak Song" by later generations was largely because of Song Taizong.
Zhao Kuangyin wants to redeem "Sixteen States" with the money from the pile bank, because before this plan was put into practice, Zhao Kuangyin suddenly died strangely and the cause of death was unknown. The history books recorded six words: "The emperor collapsed in the Hall of Long Live". Later, Zhao Kuangyin's third brother, Zhao Guangyi, inexplicably announced that he wanted to be emperor, and the history of the Song Dynasty entered the Song Taizong era.
References: History of Song Dynasty