In September 1130, hundreds of thousands of troops of the Southern Song Dynasty and the Jin Dynasty fought a decisive battle in Fuping, Shaanxi, known in history as the "Battle of Fuping". The details of this battle have been introduced before, and it ended in the fiasco of the Southern Song Dynasty. However, the battle of Fuping had a very far-reaching impact on the Southern Song Dynasty, and it can even be said that it affected the entire situation of the Song-Jin War. Some people even think that due to the fiasco in the Battle of Fuping, the Northern Expedition of the Southern Song Dynasty was doomed to fail.
The main reason why the Battle of Fuping was able to affect the song and Jin war situation was that after the end of this battle, the Jin army took advantage of the victory to launch an offensive and soon occupied the Wulu area of Shaanxi. In the Southern Song Dynasty, there were only five prefectures left, as well as several places in Shangyuan and Fangshanyuan. At the same time, hundreds of thousands of Song troops collapsed, the army was scattered, and many generals actually led the surrender of the Jin Dynasty. Since then, the Sichuan-Shaanxi front has been completely on the defensive. The loss of the Five Roads in Shaanxi directly affected the strength of both the Song and Jin dynasties.
First, the cradle of elite soldiers
The north of Shaanxi Fifth Road is the Dangxiang people, and the west is the Tubo tribes, so the local people are fierce and have a strong martial spirit. From the middle of the Northern Song Dynasty, the "Western Army" stationed on the Fifth Road in Shaanxi became the most elite unit of the Song Army. The "Western Army" has been fighting against the Western Xia for a long time and has undergone the baptism of war, so it has a strong combat effectiveness. For this situation, the Song people knew it well, for example, Song Gaozong Zhao Zhuo once said: "The five roads of Shaanxi are the best soldiers."
In addition, the Shaanxi Fifth Road is also "rich" in fierce generals. Since the middle of the Northern Song Dynasty, there have been many famous general families in the Five Roads of Shaanxi, such as the famous "Seed Family General". In the early years of the Southern Song Dynasty, except for Yue Fei, almost all the others were from the Wulu region of Shaanxi, including Wu Jie, Wu Xuan, Han Shizhong, Zhang Jun, Liu Guangshi, Liu Kun, Guo Hao, Yang Zheng, Li Xianzhong, and so on, and even their descendants were still active in the army of the Southern Song Dynasty. If you lose the Shaanxi Five Roads, you will no longer be able to get so many elite soldiers.
2. The base for war horses and military food
In addition to providing elite soldiers, Shaanxi Wulu was also the main source of warhorses and military food for the Northern Song Dynasty. Although the economic status of Shaanxi Wulu has declined, it is still a fertile field, and "the grain and wheat produced are widespread". It can be seen from this that the agriculture of Shaanxi Wulu is still very developed, and grain production can meet the needs of the army to a certain extent. In addition, Shaanxi Wulu was also the main supply base for Song Dynasty warhorses, and during the Northern Song Dynasty, Shaanxi Wulu was "40,000 horses in length".
During the reign of Emperor Xiaozong of Song, the second emperor of the Southern Song Dynasty, Yu Yunwen, an official of the main war faction, was heavily used. At that time, Yu Yunwen proposed to Song Xiaozong that "the situation is convenient, like Shaanxi", "to build soldiers, horses, and grain can strengthen the country's prestige, and can be paid enough." Therefore, Song Xiaozong sent Yu Yunwen to Sichuan, intending to advance into the Five Roads of Shaanxi. The fiasco of the Battle of Fuping made the Southern Song Dynasty lose the source of elite soldiers, fierce generals, and warhorses, without these strategic resources, what northern expedition would it take?
Third, the base of the Central Plains
The Northern Expedition of the Southern Song Dynasty originally had three routes, marching north from the Huai River Valley, advancing north from the Xiangyang area, and the other way was from Shaanxi to Henan. The first two routes were more difficult to march, mainly because the road was long, coupled with the fact that the Southern Song Dynasty was dominated by infantry, the marching speed was slow, and the logistics supply was also a problem. The Guanzhong area is easy to defend and difficult to attack, in the words of Yu Yunwen, "if you want to abide by the rules, you have dangers to be afraid of, and if you want to fight, you have the resources to rely on."
In the early years of the Southern Song Dynasty, Li Gang, the minister of the main war faction, once said, "Since the lord of the ancient Zhongxing, starting from the northwest, is enough to have a southeast according to the Central Plains, and from the southeast, it cannot have a northwest by restoring the Central Plains." "The Five Roads of Shaanxi was a very important part of the Southern Song Dynasty's restoration of the Central Plains, but due to the fiasco at the Battle of Fuping, the Five Roads were lost, and the strength of the Song army on the Sichuan-Shaanxi front was greatly reduced, and it was forced to turn into a defensive state. After the Battle of Fuping, if it were not for the Wu brothers sticking to Shangyuan, the Southern Song Dynasty would have faced a greater threat.
References: 1. "History of Song"; 2. "Records of the Year since Jianyan"