(初不得三/초부득삼) [1]
영락/永樂 14-7 (404-7)
After war was formally declared in 404, both the Yan and Goguryeo planned to conduct offensive maneuvers in order to seize more territory, although they also planned to use the border fortifications to withstand sieges if necessary. They also attempted to recover territory which they considered to be rightfully theirs. As neither had amassed a comparable number of troops before, expectations were also running high on both sides, temporarily boosting morale. However, their ultimate objectives were different. The Yan planned to head deep into Goguryeo territory, then sack the capital in order to deprive them of resources, while Goguryeo aimed to seize both the Liaodong and Shandong (山東) peninsulas in order to gain more favorable positions along the coastlines. These approaches ultimately meant that the Yan decided to focus its attacks on one or two fortifications in order to break through the defense, while Goguryeo spread out its forces in order to overwhelm the enemy by coordinating attacks on different regions [2].
Damdeok initially attacked the Yan in November [3], which caught the latter by surprise, as although it had mobilized most of its forces, the sudden change in plans, along with the instability in the west, took the generals another month to transfer them to the east. The soldiers were also undergoing their training exercises when the attack was launched, so the lack of preparation led the Yan to suffer several losses at the outset, eventually losing most of the Liaodong Peninsula, and also causing them to withdraw from the Yan Commandery (燕郡) [4]. Although Murong Xi had expected both sides to clash sometime in the following year, he was shocked to hear that the eastern region had been lost even before he could head to the area, and executed some of his generals for their inability to control the gradually deteriorating situation. Meanwhile, the court finally began to fully support the ruler's decisions due to the urgency of the situation, and began to work together with the army in order to adjust their military strategies. In January of the following year, they finally managed to regain the offensive for the first time in years by attacking Yodong Fortress (요동성/遼東城) [5] in full force.
However, Murong Xi was unable to comprehend that he needed to move as quickly as possible in order to succeed against Goguryeo. Instead, he ordered his men not to climb the walls, and prepare smoothing the path to the gate, so that he could enter triumphantly in his chariot with his consort [6]. This mindset caused the Yan to lessen their attacks in order to make preparations, which led the defenders to strengthen their positions within the fortress without worrying about the enemy entering from the top. Ultimately, the attackers were repelled, and further skirmishes failed as well, causing them to retreat entirely without any gains. On the other hand, Goguryeo began suffering from famine and droughts around July, causing the available crops to temporarily dwindle, and forced them to maintain a mostly strict defensive position in order to conserve resources. Around December, the Yan finally decided to attack Beili, one of Goguryeo's vassals, in order to extract some concessions, but the soldiers became apprehensive about attacking a large number of nomadic calvary, and instead shifted its focus to Mokjeo Fortress (목저성/木抵城) in Goguryeo [7]. However, after marching though three thousand li in freezing conditions, the soldiers were low in morale, and only made half-hearted attempts to assault the fortress before retreating once more.
As Damdeok was determined to break the stalemate and prevent the Yan from becoming a greater threat in the future, he began to plan out a more comprehensive strategy by requesting troops from his vassals as well. This brought the force to 80,000, and after adding those already present within the fortresses, the total came to around 100,000. The ruler then toured the country in order to view the training exercises carried out in numerous regions for several seasons. He also ordered more ships to be constructed, as he planned to attack both the northern and southern regions at the same time, allowing him to venture into Youzhou (幽州), along with the Shandong Peninsula [8]. Meanwhile, he directed some workers to repair the palace, as some of the structures had remained for several decades, and he wanted to impress the mercenaries into devoting their efforts for a state that had access to a significant amount of resources. By the end of the year, preparations had been finalized, and after the generals were assigned to each division, and the individual soldiers gathered within or near Guknae Fortress, the invasion was launched in three waves in January of 407.
The first two waves, each composed of about 40,000 troops [9], simultaneously attacked the Yan from the northeast and southeast, while the remaining 20,000 remained inside the fortresses along the western border, and prepared to send reinforcements. Although the Yan managed to gather more than 90,000 soldiers in order to confront the invaders, they were thoroughly beaten back by the combined attacks from land and sea, and the southern areas were swiftly overrun in less than a month, as the defenders were less concentrated in that region. The numerous purges conducted by the Yan rulers also took their toll, as fear of executions caused many Yan generals to defect to the other side, where they were valued for their knowledge of Yan strategies. Although the continuous battles eventually tired out the coalition by the end of March, and Murong Xi was barely able to hold out after stalemating in a buffer zone around Longcheng (龍城) [10], its former capital, it was the beginning of the end for the Yan. Although the western alliance, now headed by the Tuoba Wei and Later Qin after a brief skirmish between the two, failed to seize more territory due to conflicts among the states, all of the states in North China now ceased to view the Yan as a dominant power after its string of catastrophic defeats.
When the Yan court finally came together after Goguryeo agreed to retreat, all of the members remained silent, causing the ruler to attempt to explain the logic behind his decision, and requested the ministers for their opinions on why the state had been unable to stem the powerful tide. However, most of them either gave terse replies, or requested the ruler to punish them, as they had been unable to foresee the gloom that was now upon them. Unable to understand what went wrong, or agree on a plan for the future, Murong Xi eventually dismissed everyone, failing to notice that some of them had already begun to scheme behind his back. A few months later, his consort passed away, which only worsened the situation, as he greatly mourned her loss to the point that during her funeral, he hugged his deceased wife. He later issued an order to everyone to remain in mourning for days, with the penalty of death, which only convinced the people that his loss was brought on by his costly campaigns. Later, those closest to the ruler noticed that he began to pace around aimlessly while mumbling to himself, and eventually became less and less aware of his surroundings. Rumors eventually began to spread that he was beginning to lose touch with reality, causing the plans for his overthrow to intensify. When Murong Xi later announced plans to leave the capital, Feng Ba (馮跋), a general of Han Chinese descent, staged a coup during his absence, and installed Murong Yun (慕容雲) on the throne. Although the deposed ruler attempted to retake the capital by attacking the north gate, it was ultimately repulsed, and after the army scattered, he was hunted down and executed. He was only 23 years old.
[1] Literally means “first not achieve three”, and an English equivalent would be “third time's the charm.” The origin is unknown, although it is presumably taken from one of the Chinese classics, as many of the sayings have been recorded before the Qin dynasty.
[2] During most, if not all, of the Yan's offensive maneuvers, it sought to attack Goguryeo's capital by bypassing most of the fortresses, which allowed the latter to recover within a few decades, while Gwanggaeto aimed for the long term by systematically capturing most of the fortresses in Liaodong, then passing the Liao River to seize other territory. However, the former method required minimal resources, while Goguryeo's plans required patience in order to achieve its objectives.
[3] While the Yan had continuously attacked Goguryeo during the winter, the latter was used to attacking during the spring or summer, although it never seriously conducted an expedition to the west, so this assault would have been unexpected for the defendants.
[4] This region was located somewhere between the Liao River and what is now Beijing, although the exact region is unknown.
[5] Located in modern-day Liaoyang, Liaoning.
[6] This incident actually occurred IOTL, and was recorded in the Zizhi Tongjian, Book of Jin, and the Samguk Yusa.
[7] Located in modern-day Fushun, Liaoning.
[8] Youzhou was located in what is now the area around Beijing. IOTL, the Shandong Peninsula was occupied by the Southern Yan, which broke off from its northern neighbor soon after its defeat at Canhe Slope, and had cordial relations with Goguryeo.
[9] IOTL, Goguryeo attacked the Yan with 50,000 troops, but would have probably needed more ITTL due to the latter's control over Shandong.
[10] Modern-day Chaoyang, Liaoning.
