The Chanyuan Agreement
In 988 Zhao Hen, the Song Emperor Zhenzong, succeeded to the throne, becoming the third emperor of the dynasty. During his reign, the situation along the northern borders grew more and more tense. Liao troops constantly invaded from the north, harassing and robbing the people, who, beyond all endurance, were crying out for help.
In 1004 the Liao once again amassed 200,000 troops. Under the command of the Liao Emperor Shengzong, along with his mother Empress Dowager Xiao, they set off from Youzhou and marched south to invade the Song. The Liao troops swiftly drew close to Chanzhou Prefecture (today's Puyang County, Henan Province) on the Yellow River, directly threatening the capital, Bianliang. Messages pleading for help flooded Bianliang. The panicstricken emperor summoned his courtiers to work out a strategy. Someone immediately came up with the suggestion to move the capital elsewhere, which met with strong opposition from Kou Zhun, the Prime Minister. Kou Zhun had been awarded the position of Vice Prime Minister at the age of 31. However, being a man upright in his ways, he had offended Emperor Taizong. After a time he was demoted to a post in Dengzhou Prefecture (today's Dengxian County, Henan Province).
In 1004, with the tensions in the border areas rising, Kou Zhun was appointed Prime Minister, in this time of emergency. Over the issue of Liao, Kou Zhun had always stood by the idea of resolute resistance. Displeased with the passive and concessionary attitude of the ministers, he advised Emperor Zhenzong: "Your Majesty, what we should do now is not move the capital, but work in concert to confront the challenge from Liao. If you take the field yourself, in command of the army, that will boost their morale and smash the enemy with one blow. Otherwise, how would we keep our territories intact, should the Liao troops fight their way over and storm into Bianliang, demoralizing our army?" After balancing the priorities, the emperor decided to act on Kou Zhun's proposal, and take command of the expedition himself. He also announced to his courtiers, "From today, no one is to talk of moving the capital in my presence."
The Song Emperor Zhenzong led his army to Weicheng (today's Huaxian County, Henan Province). The garrison forces were exhausted, after being caught in days of fierce fighting. The emperor's arrival greatly lifted their spirits. They beat off the Liao attacks, killing Xiao Dalan, an important figure in Liao, and frustrating the momentum of the enemy.
After passing on overall command to Kou Zhun, Zhenzong took up residence m a makeshift camp. The Song army scored a series of victories. The Liao troops, after besieging the town for days, simply could not break through, thus their spirits fell, and the attacks ceased. The situation began to turn favorable for the Song. At this moment, Kou Zhun believed that they should take the advantage and drive the Liao troops north, to expand on what they had achieved. However, Zhenzong wanted to play it safe and ordered his subordinates to negotiate a peace agreement with Liao. When Kou Zhun heard the news, he became so enraged, he almost fainted.
The peace agreement was signed in 1005, historically referred to as the "Chanyuan Agreement," as it was signed in Chanyuan. The Song Dynasty was granted a fragile security at the cost of self disgrace. After the agreement went into effect, Kou Zhun was dismissed from the post of Prime Minister. Emperor Zhenzong ordered troops stationed in the frontier areas to be reduced by large numbers, with no military preparations made along the borders. During the reign of Song Emperor Renzong, this appeasement policy continued; border defense was, to a great extent, neglected; much of the defense works became dilapidated from years of disrepair; the old weaponry was no longer suitable for any meaningful offensive. In 1042 the Liao Emperor Xingzong deliberately spread word that he would send troops south, intending to exact greater annual tribute from the Song. The Song Emperor Yinzong did not dare to offend, hastily promising to yearly hand over 100,000 more bolts of silk and 100,000 more taels of silver. The Northern Song Dynasty once more had to swallow humiliation and plead for peace under the threat posed by the Liao. After that, for a long period, no major battles broke out between the two countries.