뉴스레터

The History of Goryeo includes a biography of Yoon Kwan (尹瓘, ?~1111) which is mostly about his campaigns to conquer Jurchen. Goryeo made two attempts at the conquest of Jurchen, one during the days of King Sukjong and the other during the days of King Yejong. Yoon Kwan fought in battle against the Jurchens at both times. He was close to both kings and dreaming of expanding his country's territory by conquering Jurchen. "Let me command the army to destroy the enemy's fortresses so I can restore honor for my country by expanding its territory," he said.

The Jurchens were living scattered across northeast Goryeo. While many of them stayed in their original habitation and depended on Goryeo for a living, some of them chose to immigrate into Goryeo and naturalize as its citizens. Goryeo provided these immigrants with houses and land so that they could settle down and make a living. This situation would change when the Wanyan tribe (完顔部) began to unify the rest of the Jurchens during the days of King Sukjong. Wuyashu (烏雅束) of the Wanyan tribe ruled over the Jurchen villages subjugated by Goryeo and stopped the Jurchens from depending on Goryon. A confrontation between Goryeo and Jurchen became inevitable.

In 1104 (the 9th year of the reign of King Sukjong), the Jurchen horse troops had marched down as far as Jeongju (定州) in Dongbukmyeon (present-day Hamgyeong Province in North Korea) and stationed themselves outside the gateway. King Sukjung sent Lim Gan (林幹) to fight them off, but he lost. Then Yoon Kwan was appointed and sent as commanding general, but he did not win, either, because, as he would explain later, the infantry-focused army of Goryeo was outmatched by the cavalry-focused army of Jurchen.

Building a Strong Base of Military Power to Fight Jurchen and Control Noble Civil Servants

King Sukjong decided to conquer Jurchen and made plans with Yoon Kwan for a large-scale expedition. He wanted to form a strong base of military power through war and use a war footing to control noble civil servants. At Yoon Kwan's suggestion, King Sukjong established a special military organization called Byeolmuban. which consisted of a cavalry force (Shingigun) and an infantry force (Shinbogun) made up mainly of nobles and non-slave farmers, and a Buddhist force (Hangmagun), as well as other special units. While training the military and ensuring to keep them well supplied with food, he formulated strategies to attack the Jurchens.

A war where Byeolmuban was mobilized to fight broke out during the days of King Yejong, the successor to King Sukjong. This war was waged in part because of the hidden intention of King Yejong and Yoon Kwan to keep the force of noble civil servants in check. In late 1107 (the 2nd year of the reign of King Yejong), the king appointed Yoon Kwan marshal and Oh Yeon-chong vice marshal. As the leader of Byeolmuban, Yoon Kwan was in command of the 170,000-strong army, and captured 135 strategic Jurchen positions and killed or took prisoners about 5,000 Jurchens. Yoon Kwan marched past Jeongju, occupied the Hamheung Plain, and reached Gilju over the pass of Maunryeong.

Yoon Kwan sent commanders to the occupied areas to build nine fortresses and establish the boundaries of territory. Specifically, fortresses were built first in Hamju, Yeongju, Eungju, Bokju, Gilju, and Gongheomjin, where a monument was erected to mark the border between Goryeo and Jurchen. In the following year, Hamju became a strategic military base with the establishment of Daedodokbu. And the four districts, including Yeonju, and Gongheomjin were organized as a line of defense. Additional fortresses were built in Euiju, Tongtaejin, and Pyeongyungjin. The fortresses built in theses 'ju's' and 'jin's' are collectively referred to as 'Yoon Kwan's Nine Fortresses.' These areas were populated with people relocated from the south. There is no consensus on the locations of the Nine Fortresses and the extent of the occupied areas. A majority view is that the Nine Fortresses were located in a region of Hamgyeong Province that extended to the pass of Maunryeong. Some assume that their sphere of influence reached as far north as across the Duman River.

Goryeo's control of the whole area of Hamgyeong Province sparked strong resistance from the Jurchens living there, because they had been deprived of their farming land as the basis for a livelihood. Fierce battles ensued in areas with newly built fortresses, including Yeongju, Ungju, and Gilju. Yoon Kwan captured 340 Jurchen prisoners, horses, and cattle and offered them to the king. In April 1108, Yoon Kwan made a triumphant return to Gaegyeong, the capital of Goryeo.

The tomb of Yoon Kwan

Yoon Kwan's Nine Fortresses Contributed to Goryeo's Growing Perception of its Territory

But Yoon Kwan had to go back to battlefield in just three months as the Jurchens struck back. Located far away from one another in the vast expanse of the newly occupied territory, the Nine Fortresses were becoming increasingly difficult to defend. In this expedition, Yook Kwan failed to subjugate the Jurchens, who at the time were keen on negotiating peace terms with Goryeo to regain their lost territory. They promised the payment of a regular tribute to Goryeo on the condition that the Nine Fortresses would be returned to them.

In Goryeo, voices were raised in opposition to war with Jurchen. King Yejong summoned a meeting of the six ministers for the discussion over whether or not the Nine Fortresses should be returned to Jurchen. A majority was of the opinion that an amicable relationship should be established with Jurchen. In July 1109 (the 4th year of the reign of King Yejong), Goryeo made the decision to return the Nine Fortresses to Jurchen. This meant that the campaigns led by Yoon Kwan for the conquest of Jurchen had ended in failure. And that his dream of expanding Goryeo's territory through expedition had been shattered. A number of noble civil servants blamed Yoon Kwan for the defeat. King Yejong divested Yoon Kwan of his title as a vassal of merit and removed him from office, only to reinstate him and restore his honor in the following year (1110).

Yoon Kwan died in 1111 (the sixth year of the reign of King Yejong). Four years later, in 1115, the Jurchens established the Jin Dynasty, which emerged as a new power in East Asia. Goryeo and Jin took a pledge of brotherhood and then established a tributary system between them without military confrontation. Historian Shin Chae-ho gave Yoon Kwan credit for helping the two countries maintain a peaceful relationship. He explained that since Yoon Kwan had fought the Jurchens, the Jin Dynasty had refrained from invading Goryeo. And with Yoon Kwan's experience in developing the Nine Fortresses, Goryeo's perception of its territory grew. In 1368 (the 5th year of the reign of King Gongmin), Goryeo recaptured Dongbukmyeon and went on to occupy the whole areas of Hamgheung and Gilju in the north. And Goryeo claimed to the Ming Dynasty that the area that extended up to Guilju was its inherent territory. In other words, Yoon Kwan's establishment of the Nine Fortresses as far north as Gilju allowed Goryeo's perception of its territory to grow.