Emperor Taizong of Song

Emperor Taizong personally led the campaign against Northern Han in 979 and ordered the flooding of enemy cities by releasing the Fen River. The Northern Han ruler Liu Jiyuan was forced to surrender, thus ending all the kingdoms and dynasties in the Five Dynasties and Ten Kingdoms period.

Having conquered Northern Han in 979, Emperor Taizong took advantage of the momentum and launched another military campaign against the Khitan-led Liao dynasty. In May 979, Emperor Taizong embarked on his campaign from Taiyuan and took Zhuo and Yi Prefectures easily. He besieged Yanjing (present-day Beijing) after the success. However, the siege failed when the Liao defending general Yelü Xuegu defended the fortress firmly.

Concurrently, Liao reinforcements led by Yelü Xiuge arrived from the Gaoliang River region, west of Yanjing. Emperor Taizong ordered his army to attack the reinforcements. Initially, he received reports that the Liao army was suffering heavy casualties. He ordered a full assault on the Liao army as he thought that the whole battle was under his control. Just then, Yelü Xiuge and Yelü Xiezhen's armies attacked from two sides. Yelü Xiuge concentrated on attacking Emperor Taizong's main camp. Emperor Taizong was shocked and evacuated from the battlefield. During the evacuation, the Song army was divided and obliterated by the Liao cavalry.

Amidst the onslaught, Emperor Taizong fled towards Yi Prefecture and arrived there safely with his generals protecting him. He sustained an injury from an arrow and was unable to ride on his horse and had to travel by carriage back to Ding Prefecture. Emperor Taizong ordered a retreat after that. The Song army was without a commander as Emperor Taizong was separated from his troops. The troops suggested that Emperor Taizu's eldest son, Zhao Dezhao (Emperor Taizong's nephew), be the new emperor. Emperor Taizong's suspicions were raised when he heard that and eventually he ordered Zhao Dezhao to commit suicide.

The Battle of Gaoliang River was significant as it was one of the major contributing factors to the Song dynasty's decision to adopt a defensive stance. The early Song army suffered its first major defeat in battle. Meanwhile, Emperor Taizong was also troubled by the possibility that Zhao Dezhao would launch a coup. After the battle, Emperor Taizong personally inspected and focused more on the development and strengthening of his military forces. He ignored his subjects' advice and regarded state affairs as of lower importance. He also limited the power and control that the imperial family and military officers had over the army.

Monument in memory of renovating the Temple of Confucius in Qufu. Year 8 of the Taipingxingguo era (AD 983) (top of the stele)

Monument in memory of renovating the Temple of Confucius in Qufu. Year 8 of the Taipingxingguo era (AD 983) (tortoise pedestal)

After the death of Emperor Jingzong of Liao in 982, the 12-year-old Emperor Shengzong of Liao ascended to the throne of the Liao Dynasty. As Emperor Shengzong was too young to rule the kingdom, Empress Dowager Xiao became the regent. Emperor Taizong decided to launch the second campaign against Liao in 986, following the advice of his subjects.

During this time, Zhao Yuanzuo, Taizong's oldest son became insane after the death of his uncle, Zhao Tingmei, and that he was not invited to the Double Night Daylight Feast which ultimately caused Yuanzuo to burn down the palace.[8] As a result, Taizong, under the pressure of his censors demoted Yuanzuo to commoner status and exiled him.[8] This, was changed when 100 officials rejected Yuanzuo's exile and pressured Taizong to let Yuanzuo remain in the palace.[8] Three officials who had responsibility for Yuanzuo asked to be punished by Taizong in which Taizong said "This son, even I have been unable to reform through my teaching. How could you guide him?" in response.[8]

In 983, the practice of officials tutoring imperial princes began under his reign.[8] One notable case was Emperor Taizong's son Zhao Yuanjie and his tutor Yao Tan (935–1003) in which Yao constantly berated the young prince for being idle and lazy causing resentment from the prince.[9] Yao attempted to complain to Taizong who said "Yuanjie is literate and enjoys learning; that should be sufficient to make him a worthy prince. If when young he is immoderate, then it is necessary to have entreaties to rein in his ridicule. But if you slander him without good reason, how is that going to help him?"[9] However, Yuanjie under peer pressure from his friends feigned illness and began neglecting his duties. Concerned, Taizong checked the Prince's progress daily.[9] He summoned Yuanjie's wet nurse after the Prince still was "ill" for a month with the wet nurse stating "The Prince is basically not sick; it's just that with Yao Tan checking up on him, he can seldom follow his inclinations, and thus has become sick."[9] This enraged Emperor Taizong ordering her to be caned.[9]

Emperor Taizong remained in Bianjing and directed the war there without personally entering the battlefield. He split the army into three sections – East, Central and West. The East Army was led by Cao Bin, the Central Army by Tian Zhongjin and the West Army by Pan Mei and Yang Ye. All the three armies would attack Yanjing from three sides and capture it. The campaign was termed as the Yongxi Northern Campaign as it took place in the third year of the Yongxi era of Emperor Taizong's reign.

The three armies scored some victories initially but they became more divided later as they acted individually without cooperation. Cao Bin took the risk by attacking without the support of the other two armies. He succeeded in taking Zhuo Prefecture but the lack of food supplies forced him to retreat. As there was miscommunication between the three armies, the East Army attacked Zhuo Prefecture again. However, this time, Empress Dowager Xiao and Yelü Xiuge each led an army to support Zhuo Prefecture. The East Army was inflicted with a crushing defeat and almost completely destroyed.

Emperor Taizong was aware that the failure of the East Army would affect the entire campaign and he ordered a retreat. He ordered the East Army to return, the Central Army to guard Ding Prefecture and the West Army to guard four prefectures near the border. Following the defeat of the East Army, the Liao army led by Yelü Xiezhen attacked them as they retreated. The West Army led by Pan Mei met Yelü Xiezhen's army at Dai Prefecture and faced another defeat at the hands of the Liao army. The two commanders of the West Army started to argue about retreating. Yang Ye proposed that they should retreat since the East and Central Armies had already lost the advantage following their defeats. However, the other generals on Pan Mei's side began to doubt Yang's loyalty to Song as Yang Ye used to serve Northern Han. Yang Ye led an army to face the Liao troops but they were trapped and Yang committed suicide eventually. Pan Mei was supposed to arrive with reinforcements to support Yang but he failed to do so.

Emperor Taizong ordered another retreat following the Song armies' defeats by Yelü Xiuge and Yelü Xiezhen. The failure of the second campaign was attributed to the miscommunication between the three armies and their failures to operate together. Besides, Emperor Taizong had also restricted the decisions of his generals as he had arbitrarily planned the whole campaign against Liao and his generals had to adhere to his orders strictly. These failures led to internal rebellions which were crushed swiftly.

In 988, the Liao armies led by Empress Dowager Xiao attacked the Song border again. Emperor Taizong did not order a counter-attack and merely instructed the troops to defend firmly.