[Lee Sang-hoon's Korean History] Without the Frontier General Jeong Shinyong... There Would Have Been No Hero Gang Gamchan Either

993nyeon 1cha chimnip Seo Huiui Gangdong damban
1010nyeon 2chaneun Yang Gyu gibyeongdaega makhae

Sanghoon Lee, Professor of Military Science at the Korea Military Academy

The Goryeo dynasty and the Khitan engaged in large-scale wars over approximately 30 years. Although the Khitan invasions are sometimes divided into six phases, they are generally understood as three major invasions. The first invasion began in 993, followed by the second in 1010, and the third in 1018. During the first invasion, Seo Hui acquired the Gangdong (江東) Six Prefectures; in the second invasion, General Yang Gyu's cavalry played a significant role; and in the third invasion, General Gang Gam-chan achieved a great victory.

When thinking of the Goryeo-Khitan wars, Seo Hui, Yang Gyu, and Gang Gam-chan are commonly recalled. However, there was a figure named Jeong Sin-yong (鄭神勇) who was active between the second and third Khitan invasions. Jeong Sin-yong died in battle during the Khitan invasion of 1014?1015.

On September 13, 1014, the Khitan commander Yi Song-mu (李松茂) demanded the return of the Gangdong Six Prefectures. When Goryeo showed little response, on October 6, the Khitan general So Jeok-ryeol (蕭敵烈) invaded Tongju (通州). At this time, General Jeong Sin-yong of Heunghwajin (興化鎭), along with Byeoljang (Deputy Commander) Ju Yeon (主演), repelled the Khitan forces. It is said that over 700 Khitan soldiers were beheaded and many drowned in the river during this battle.

The Khitan invasions continued into the following year. On January 22, 1015, the Khitan army besieged Heunghwajin. At this time, General Go Jeok-yeo (高積餘) and Jo Ik successfully defeated the Khitan forces. However, on January 23, the Khitan attacked Tongju again. Considering the one-day gap between the siege of Heunghwajin and the attack on Tongju, it seems that while some Khitan troops were engaged in the siege, the main force continued southward. Eventually, after spring passed, the Khitan forces withdrew. Rewards were given on July 13.

The Dobyeongmasa (都兵馬使, Commander of the Capital and Military Affairs) reported, "General Jeong Sin-yong, Im Yeong-ham (林英含), and approximately 12,500 soldiers all contributed to defending the border, so we request that their official ranks be elevated and they be rewarded." King Hyeonjong of Goryeo approved this. Of course, it is unlikely that all 12,500 soldiers received rank promotions, but the two generals likely had their ranks raised, and the remaining soldiers probably received individual rewards.

The Gangdong Six Prefectures previously acquired by Goryeo were Heunghwajin (Uiju), Yongju (Yongcheon), Tongju (Seoncheon), Cheolju (Cheolsan), Gwiju (Gwiseong), and Gwakju (Gwaksan). The circumference of each fortress was as follows: Heunghwajin 699 kan (approximately 1.3 km), Yongju 1,573 kan (approximately 2.8 km), Cheolju 789 kan (approximately 1.4 km), Gwiju 1,507 kan (approximately 2.7 km), and Gwakju 787 kan (approximately 1.4 km).

Heunghwajin is the first place the Khitan army encounters after crossing the Yalu River. Passing through Heunghwajin, which serves as a gateway, Tongju lies at the center of the transportation route. Based on Tongju, Gwiju is located to the northeast, Gwakju to the southeast, and Cheolju and Yongju to the northwest. The Khitan army's persistent attacks on Tongju after passing Heunghwajin are partly due to this strategic positioning. The large-scale battle between the Khitan forces and the Goryeo army led by Gang Jo during the second invasion in 1010 also took place in Tongju.

In 1015, Yi Song-mu's renewed demand for the Gangdong Six Prefectures
Jeong Sin-yong defended Goryeo's gateway Heunghwajin
Killed over 700 enemy soldiers but died in battle
Laid the groundwork for Gang Gam-chan's great victory in 1018

The Khitan invasions resumed in the autumn. On September 7, 1015, Yi Song-mu again demanded the return of the Gangdong Six Prefectures. Just five days later, on September 12, they attacked Tongju once more. On September 16, General Jeong Sin-yong of Heunghwajin, Byeoljang Ju Yeon, Sanwon (staff officer) Im Eok (任憶), Gyowi (校尉) Yang Chun (陽春), Ta-uiseung (Deputy Royal Physician) Son Gan (孫簡), and Ta-sa-seung (Deputy Historian) Kang Seung-yeong (康承潁) struck the rear of the Khitan forces. Although they killed over 700 Khitan soldiers, six, including Jeong Sin-yong, were killed in action.

On September 20, the Khitan attacked Yeongju Fortress (寧州城) south of the Cheongcheon River but failed and retreated. On September 23, General Go Jeok-yeo, Generals So Chung-hyeon (蘇忠玄) and Go Yeon-jeok (高延迪), Sanwon Kim Geuk (金克), and Byeoljang Gwang Cham (光參) pursued the Khitan forces but were all killed. At this time, the Khitan captured the Byeongmapangwan (兵馬判官, Military Commissioner) Wang Jo (王佐) and Noksan (錄事, Recorder) No Hyeon-jo (盧玄佐) as prisoners.

The Khitan invasions of 1014?1015 are recorded more briefly compared to the first, second, and third invasions. This is likely because Goryeo's top generals Jeong Sin-yong and Go Jeok-yeo, as well as generals So Chung-hyeon and Go Yeon-jeok, died, and even the Military Commissioner was captured. Although Goryeo repelled the Khitan invasions, the human losses were significant. They pursued the retreating Khitan forces but suffered a devastating defeat, which may explain the sparse records.

The "History of Liao" (遼史), in the "Records of Food and Goods" (食貨志), states, "When the Khitan army marches and reaches the enemy's fortress but finds the defense strong and cannot attack, they shoot arrows and beat drums loudly to feign an attack." It also says, "If the enemy closes the gates and defends firmly, there is no fear of being blocked ahead, so the army advances." In other words, to conduct mobile warfare centered on cavalry, they leave only a small force to harass the enemy while the main force advances rapidly.

The battles of 1014?1015 could be seen as a "Pyrrhic victory" for Goryeo due to the heavy human losses. However, considering the overall situation, the movements of the Goryeo army were remarkable. On October 6, 1014, when the Khitan attacked Tongju, Jeong Sin-yong's forces at Heunghwajin struck the Khitan rear, forcing them to retreat. On January 22, 1015, the Khitan first besieged Heunghwajin, and on the 23rd, the main force attacked Tongju. At this time, Go Jeok-yeo's troops lifted the siege of Heunghwajin. The Khitan eventually abandoned the attack on Tongju and withdrew.

On September 12, 1015, the Khitan attacked Tongju again. On the 16th, Jeong Sin-yong's forces at Heunghwajin struck the Khitan rear. Unlike the 1014 battle, the Khitan seemed somewhat prepared this time, and the fighting was fierce. Jeong Sin-yong died in this battle.

However, due to the attacks by Heunghwajin's forces, the Khitan could no longer sustain their offensive. On September 20, the Khitan vanguard was attacking Yeongju Fortress (Anju) across the Cheongcheon River. With their supply and retreat routes endangered, the Khitan had no choice but to withdraw again.

The Khitan attack on Yeongju Fortress on September 20, 1015, occurred after they had broken through the Gangdong Six Prefectures and advanced south of the Cheongcheon River. Had Jeong Sin-yong's forces at Heunghwajin failed to respond properly, the area north of the Cheongcheon River might have fallen into Khitan hands. The fact that Goryeo's gateway Heunghwajin did not fall easily indicates a significant shift in the battle dynamics.

In fact, during the second Khitan invasion in 1010, Yang Gyu was stationed at Heunghwajin and disrupted the Khitan rear. During the third invasion in 1018, Gang Gam-chan achieved a great victory at Heunghwajin. Thus, Heunghwajin was the foremost stronghold and strategic key point in the wars against the Khitan.

King Hyeonjong grants exceptional land to Jeong Sin-yong's family
Goryeo court specially honors his military achievements

The Khitan invasions of 1014?1015 ended. On January 10, 1016, King Hyeonjong of Goryeo rewarded the military heroes including Jeong Sin-yong. Jeong Sin-yong was posthumously appointed as Sangseo Ubokya (尙書右僕射, Right Deputy Minister of the Shangshu Department) and Sangjuguk (上柱國, Senior Pillar of the State), Ju Yeon as General, Im Eok as Jungnangjang (中郞將, Central Commandant), Yang Chun as Nangjang (郞將, Captain), Son Gan as Sangyakbungeo (尙藥奉御, Royal Medicine Attendant), and Kang Seung-yeong as Tasa-ryeong (太史令, Chief Historian). All of these were individuals who died in the September 1015 battle. Additionally, Jeong Sin-yong's son Jeong Gyun-baek (鄭均伯) was appointed Nangjang and Sangseungbungeo (尙乘奉御, Royal Carriage Attendant).

The posthumous title Sangseo Ubokya corresponds to the de facto minister of the Shangshu Department, equivalent to a Jeong 2nd rank official. Sangjuguk is a noble title granted to war heroes and is among the highest ranks. This was the highest-ranking military award granted during King Hyeonjong's reign. However, Generals Go Jeok-yeo, So Chung-hyeon, and Go Yeon-jeok, who also died in the September 1015 battle, were only recommended for rewards on July 2, 1016, following the Dobyeongmasa's proposal.

On November 1, 1016, King Hyeonjong granted 20 gyeol (결, a traditional land measurement) of good farmland to Jeong Sin-yong's household. At that time, it was unusual to reward military achievements with land rather than official titles or grain. The Khitan invasions were completely ended on March 16, 1020. King Hyeonjong also specially granted 300 seok (석, a grain measure) of grain to Jeong Sin-yong's household. From this context, it is clear how much King Hyeonjong and the Goryeo government valued Jeong Sin-yong's military achievements.

The Khitan invasions of 1014?1015 and Jeong Sin-yong's contributions are not widely known today. However, at that time, General Jeong Sin-yong was a war hero in Goryeo.

Lee Sang-hoon, Professor of Military History, Korea Military Academy