[Lee Sang-hoon's Korean History] Kim Bu-sik, Who Besieged the Seogyeong Rebels for Half a Year, Said "The Time Has Come, Build a Dosan"

The Rebellion of Goryeo's Myocheong and Its Suppression

Sanghoon Lee, Professor at the Korea Military Academy

"Gyeong (卿) possessed the talents of both civil and military affairs, took on the duties of a general and prime minister, and won the hearts of the soldiers through generosity. With profound skill and exquisite weaponry, he had already firmly established the art of control in his heart. At first, he built walls and wooden fences to give the soldiers rest, and eventually raised earthen mounds to pressure the enemy’s fortress. Ultimately, the rebel forces, seeing the situation, were destroyed on their own and surrendered helplessly."

King Injong (仁宗) of Goryeo bestowed a title upon Kim Busik, who had successfully suppressed the rebellion in Seogyeong (西京, present-day Pyongyang). He was granted the titles of Suchung Jeongnan Jeongguk Gongshin (輸忠定難靖國功臣), Geomgyo Taebo (檢校太保), Sutaiwi (守太尉), Munhasijung (門下侍中), Pansangseori Busa (判尙書吏部事), Gamsuguksa (監修國史), Sangjuguk (上柱國), and concurrently Taija Taebo (太子太保).

When Kim Busik returned victorious, Injong granted him another fine house. This was truly the highest reward for a subject. It also attests to how threatening the Seogyeong rebellion was to the Goryeo dynasty.

In January 1135, Myocheong, along with Jo Gwang and Yu Cham, rebelled against the Goryeo government in Seogyeong. This is known as Myocheong’s Rebellion. Myocheong blocked the Jabiryeong Pass and gathered troops from the Northwest region (西北面) to Seogyeong. He declared the national title as Daewi (大爲) and the era name as Cheongae (天開), completely denying the Goryeo dynasty.

King Injong appointed Kim Busik as commander-in-chief to organize the suppression army. Kim Busik led the central army, Kim Bu-ui the left army, and Lee Ju-yeon the right army, forming a three-army system and began advancing northward.

Kim Busik passed through Pyeongju (平州) and arrived at Seongju (成州). He sent proclamations to surrounding fortresses to inform them of Myocheong’s rebellion and also sent people to Seogyeong to persuade them. They began to take control of the Yanggye (兩界) region, which could cooperate with the Seogyeong rebels.

The suppression army bypassed Seogyeong and arrived at Anju (安州), where the Anbuk Daedohobu (安北大都護府) was located. As the Yanggye region wavered and turned favorable to the suppression army, the rebels began to falter. Eventually, when Kim Sunbu, the magistrate of Pyeongju, entered Seogyeong with the king’s edict, the people of Seogyeong captured and beheaded Myocheong and Yu Cham. Yun Cheom and Jo Chang-eon pleaded for clemency.

Kim Busik (left) and Myocheong

During King Injong’s reign in 1135,
Myocheong, who advocated moving the capital to Seogyeong and attacking the Jin dynasty,
rebelled after his plans were thwarted by Gaegyeong aristocrats,
declared a new national title, and gathered troops in Seogyeong.

Yun Cheom, who arrived in Gaegyeong, was soon imprisoned, and Myocheong was beheaded in the marketplace. Jo Gwang, who remained in Seogyeong, sensed he would also be punished and initiated another rebellion. In response, Injong sent Kim Bu, the Jeonjung Si-eosa (殿中侍御史), along with Yun Cheom to Seogyeong to issue royal edicts.

However, Kim Bu intimidated and threatened the Seogyeong forces rather than consoling or appeasing them. Ultimately, the people of Seogyeong, out of fear and anger, killed Kim Bu and all his attendants and locked the city gates. Kim Busik sent Lee Deok-gyeong to persuade them, but he was also killed. The rebellion resumed.

Injong ordered Jeong Seup-myeong, the Naesi Jiho (內寺祗候), and others to recruit 4,600 archers and sailors on the southwestern sea islands of Seogyeong. The plan was to ascend the Daedong River with 140 ships to prepare for enemy vessels around Seogyeong Fortress. Simultaneously, Sangjanggun (上將軍) Lee Nok-cheon was ordered to lead 50 naval ships from the West Sea to participate.

Jeong Seup-myeong’s fleet and Lee Nok-cheon’s fleet joined at Cheoldo (鐵島). Cheoldo, located in Hwangju County, Hwanghae Province, is an island at the confluence of the Daedong and Jaeryeong Rivers, a key economic and military point along the Daedong River waterway.

The tidal influence from the Daedong River estuary to Pyongyang is significant. Therefore, understanding the ebb and flow of tides is crucial. However, despite Jeong Seup-myeong’s objections, Lee Nok-cheon set sail during low tide. The suppression fleet ran aground in shallow waters before even reaching Seogyeong Fortress. At this time, the rebels set fire to about ten small boats filled with oil-soaked straw and floated them downstream.

The fire spread to the suppression fleet. Hundreds of rebels ambushed from the riverbank fired crossbows. All the military equipment on the fleet was burned. Most of the soldiers aboard drowned. Due to this mistake, the rebels’ morale soared, and they no longer feared the suppression forces.

Kim Busik judged, "Seogyeong is backed by mountains and hills to the north, surrounded by water on three sides, and the fortress is high and rugged, making a swift capture impossible." He decided to besiege Seogyeong Fortress and engage in a protracted war. The central army was stationed at Cheondeokbu (川德部), the left army at Heungboksa (興福寺) south of Seogyeong Fortress, and the right army west of Junghungsa (中興寺) north of the fortress.

Kim Busik led the government forces to suppress the rebellion,
gradually taking control of surrounding areas, causing the rebels to waver.
Though Myocheong and others were killed by Seogyeong residents,
Jo Gwang and others continued the rebellion out of fear of punishment.
As government forces threatened them, Seogyeong residents also joined in.

The rear army was positioned at the Daedong River crossing, and the front army was added east of Junghungsa. This completely encircled Seogyeong Fortress and prepared for a long siege.

Despite several attempts to attack while Seogyeong Fortress was fully surrounded, the gates did not easily open. More than half a year had passed since the siege began. Food supplies were dwindling. By October, the rebels released the elderly and women outside the fortress. The suppression forces sensed the time was ripe.

From November, the suppression forces began constructing earthen mounds (土山) for the siege, selecting a site southwest of Seogyeong Fortress. At that time, the outer wall (羅城) of Seogyeong Fortress was nearly collapsed, and the inner fortress (重城) was the frontline between rebels and suppression forces.

The suppression forces, numbering 23,200 soldiers and 550 monks, built earthen mounds of earth, stone, and timber. The mound was 8 jang (丈) high, about 70 jang long, and 18 jang wide. Calculating one jang as approximately 3 meters, the mound measured about 24 meters high, 210 meters long, and 54 meters wide. It was only a few jang away from Seogyeong Fortress. The mound was nearly completed by February the following year.

The suppression forces also prepared for the siege. They installed a massive catapult (發石機) made by Jo Eon on top of the mound. Launching stones weighing 'several hundred jin (斤)' toward Seogyeong Fortress, the fortress towers and walls were damaged. Fireballs the size of wagon wheels burned gates and outbuildings.

Cracks began to appear in the gates and walls of Seogyeong Fortress. Eventually, the suppression forces were able to enter the fortress. The earthen mound and the large catapult installed on it led to victory in the siege.

The exact form of the catapult installed on the mound is not recorded. However, Chinese sources allow us to estimate its size. During the Song (宋) dynasty, catapults were called 'po (砲),' and in the Goryeo-sa (History of Goryeo), they are recorded as 'pogi (砲機),' indicating the same siege weapon.

The largest catapult recorded in the Northern Song military manual 'Wujing Zongyao (武經總要)' was the Chilchopo (七梢砲). It measured 28 chi (尺) in length, had 125 rope strands (曳索), required 250 operators, had a range of 50 bu (步), and launched stones weighing 90?100 jin. The barrel was about 8.4 meters long, with 125 pull ropes and 250 pullers.

At that time, one bu was five chi, so the range was about 75 meters, and the stone weighed about 60 kg. Since the suppression forces launched stones weighing 'several hundred jin,' the catapult on the mound was similar to or even larger than the Chilchopo.

To suppress the rebels who had locked the fortress gate in Seogyeongseong and resisted for over half a year, Kim Bu-sik undertook the construction of an earthen fortress. Approximately 23,000 troops and 550 monks were mobilized, and the earthen fortress, completed over about three months, measured 24 meters in height, 210 meters in length, and 54 meters in width. The photo is a scene from the movie Ansi Fortress. When Emperor Taizong of the Tang Dynasty invaded Goguryeo, he employed an earthen fortress strategy to capture Ansi Fortress, but it ended in failure, and General Yang Man-chun, who defended Ansi Fortress, achieved a great victory. Kim Bu-sik suppressed the Seogyeong rebels using the same earthen fortress strategy that Emperor Taizong of Tang had also failed with.

Seogyeong Fortress, backed by mountains and hills to the north,
was judged by Kim Busik as difficult to capture quickly.
He completely surrounded it and launched multiple attacks.
After more than half a year, construction of earthen mounds for siege began.
A massive catapult was installed, launching stones weighing hundreds of jin,
leading to victory in the siege and suppression of the rebellion.

Building earthen mounds has been a siege method since ancient times. In 645, Emperor Taizong of Tang also constructed earthen mounds during the attack on Goguryeo’s Ansi Fortress, mobilizing 500,000 men over 60 days. From the mound, they could overlook Ansi Fortress.

However, the mound suddenly collapsed, pushing down the fortress walls. Goguryeo forces seized the mound and defended it. The Tang army attacked for three days to retake the mound but failed. Ultimately, they had to abandon the Ansi Fortress siege and retreat from the Goguryeo campaign.

Kim Busik succeeded where Emperor Taizong failed with the earthen mound siege method. In fact, the method was first proposed by Yun Eon, son of Yun Gwan. He also suggested a full-scale attack after the catapult weakened Seogyeong Fortress.

However, Kim Busik held the final decision-making authority on military matters and bore responsibility for military failures. He isolated the rebels with a long-term siege strategy around Seogyeong Fortress. When the rebels faced food shortages, he prepared the attack by building earthen mounds and manufacturing catapults.

Kim Busik suppressed the Seogyeong rebellion, which lasted two years, and returned to Gaegyeong in triumph. King Injong’s trust in Kim Busik was boundless. As a result, Kim Busik left his name in history by compiling the oldest historical record, the 'Samguk Sagi (History of the Three Kingdoms).'

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