How One Korean Dynasty Survived the Khitan, Jurchens, and the Mongol Empire

From the early years of its founding, Goryeo pursued a policy of northern expansion and maintained continuous relations with various powers in the northern Korean Peninsula and Manchuria.

In particular, the period from the 10th to the 14th century, when Goryeo existed, was a time of highly dynamic change in the international order of East Asia. The Song dynasty emerged in China, while powerful states successively arose in the north, including the Khitan Liao dynasty, the Jurchen Jin dynasty, and the Mongol Yuan dynasty. Amid these shifting international circumstances, Goryeo had to preserve its state by securing its national interests through diplomatic negotiations at times and fighting large-scale wars at others.

By the late Goryeo period, the situation became even more complicated. As the power of the Yuan dynasty weakened, the Red Turban Rebellion broke out in China, while raids by Japanese pirates, known as Wokou, increased sharply along the southern coasts of the Korean Peninsula.

The broad course of Goryeo’s foreign relations and conflicts with external powers can be summarized as follows:

Khitan (Liao) → Jurchen (Jin) → Mongol (Yuan) → Red Turbans and Wokou

Quick Guide: Understanding Goryeo’s Invaders 

(If you are new to East Asian history, think of Goryeo’s enemies in terms of these well-known historical archetypes)

(1) The Khitan (Liao Dynasty) – The Steppe Juggernaut

Who they were: A powerful nomadic empire from the north that commanded massive, unstoppable cavalry forces.

Western Equivalent: Think of them as the lethal Dothraki from Game of Thrones or the Huns who terrorized Europe, but with highly organized imperial administration.

(2) The Jurchen (Jin Dynasty) – The Warrior Tribes of Manchuria

Who they were: Fierce, legendary forest and mountain warriors from Manchuria. They later conquered northern China and were the direct ancestors of the Manchu people who founded the Qing Dynasty.

Western Equivalent: Similar to the Germanic tribes that fiercely resisted and eventually toppled the Western Roman Empire.

(3) The Mongol Empire – The Ultimate Conquerors

Who they were: The largest contiguous land empire in human history. Under Genghis Khan and his successors, they conquered almost the entire Eurasian continent. Goryeo faced the peak military might of this global superpower.

Western Equivalent: The apex predators of medieval warfare. No comparison needed—everyone knows the Mongols!

(4) The Red Turban Rebels – The Chaotic Insurgents of China

Who they were: A massive, fanatical Han Chinese rebel army that fought to overthrow the Mongol-led Yuan Dynasty. Their movement eventually led to the birth of the famous Ming Dynasty.

Western Equivalent: A massive peasant rebellion or religious crusade gone rogue, spilling over national borders like the chaotic mercenary armies of the European Thirty Years' War.

(5) The Wokou (Japanese Pirates) – The Vikings of Asia

Who they were: They weren't just petty thieves in small boats; they were highly organized, heavily armed maritime military forces striking from Japan, terrorizing the coastlines of Korea and China.

Western Equivalent: The Vikings. They used fast ships, specialized in brutal coastal raids, and completely paralyzed medieval trade routes just like their European counterparts.

This process was not simply a history of successive invasions by foreign enemies. It was closely connected to changes in the East Asian international order, in which regional dominance shifted from the Khitan to the Jurchen and then to the Mongols. Goryeo responded to these transformations by continually adapting its political, military, and diplomatic systems.

1. 10th–11th Centuries: Wars with the Khitan (Liao)

The greatest threat to Goryeo during its early period came from the Khitan in the north.

In the early 10th century, Yelü Abaoji unified various Khitan tribes and expanded his power. He later established the Liao dynasty, which grew into one of the major powers of East Asia.

From the reign of its founder, King Taejo Wang Geon, Goryeo pursued a policy of northern expansion based on the belief that it was the successor to the former territories and legacy of Goguryeo. Goryeo was particularly hostile toward the Khitan because they had destroyed Balhae.

The famous story that King Taejo had camels sent by the Khitan tied beneath Manbu Bridge and left to starve to death symbolically illustrates Goryeo’s hostile attitude toward the Khitan at the time.

# The First Khitan Invasion and Seo Hui’s Diplomatic Negotiations

In 993, during the reign of King Seongjong, Xiao Sunning, the Eastern Capital Governor of the Khitan Liao dynasty, invaded Goryeo with a large army.

However, the conflict was ultimately resolved through diplomatic negotiations rather than a large-scale decisive battle.

One important factor that made such negotiations possible was that the Goryeo army had been able to maintain a certain degree of military balance against the Khitan forces on the battlefield.

In the Battle of Bongsan County, the first major engagement of the First Khitan Invasion, the Khitan army defeated the Goryeo forces, and Yun Seo-an (尹庶安), a Goryeo official commanding the vanguard, was captured by the Khitan.

However, in the subsequent Battle of Anyungjin, fought near the lower reaches of the Cheongcheon River, the Goryeo forces led by Dae Do-su successfully counterattacked and defeated the Khitan army.

As the Khitan army was unable to overwhelmingly defeat the Goryeo forces and the front reached a stalemate, both sides began seeking a negotiated settlement rather than continuing the military confrontation. Against this military backdrop, diplomatic negotiations between Seo Hui and Xiao Sunning became possible.

Xiao Sunning’s demands can be broadly summarized as follows:

(1) Xiao Sunning argued that the Khitan had already occupied the former territories of Goguryeo and that Goryeo was encroaching upon Khitan territory by pursuing its policy of northern expansion. He also claimed that Goryeo had been founded within the former territory of Silla and demanded that Goryeo cede the lands north of the Daedong River to the Khitan.

(2) He also criticized Goryeo for refusing to maintain relations with the Khitan despite their geographical proximity, while maintaining relations only with the Song dynasty, the Khitan’s enemy located far across the sea.

In response, Seo Hui emphasized during his negotiations with Xiao Sunning that Goryeo was the legitimate successor to Goguryeo. He argued that the very name “Goryeo” had been chosen because the kingdom regarded itself as the successor to Goguryeo. Since the former territory of Goguryeo had extended as far as the Liaodong region, Seo Hui countered that the lands east of the Yalu River were also territories that Goryeo had a legitimate claim to inherit.

Seo Hui further explained that Goryeo had been unable to establish direct relations with the Khitan not because it had deliberately chosen to remain hostile toward them, but because Jurchen groups occupied the region between Goryeo and the Khitan, blocking the overland route between the two states. He therefore argued that if the Jurchens were driven out and a direct route between the two countries was secured, Goryeo would also be able to establish relations with the Khitan.

After concluding their negotiations over border and diplomatic issues, Seo Hui and Xiao Sunning brought their talks to a close in a friendly atmosphere.

At first, when Xiao Sunning attempted to hold a banquet for Seo Hui, Seo Hui declined, saying, “How could I enjoy a banquet while our soldiers are suffering in the field?” However, when Xiao Sunning repeatedly urged him to accept, saying, “Since ministers of our two countries have met, we should observe the proper courtesies,” Seo Hui eventually agreed.

The two men then spent seven days attending banquets and interacting with each other before parting ways. After successfully concluding the negotiations, Seo Hui prepared to return to Goryeo. As a gesture of goodwill, Xiao Sunning presented him with a considerable number of gifts, including 10 camels, 100 horses, 1,000 sheep, and 500 bolts of silk.

Xiao Sunning reported to the Khitan court a proposal under which Goryeo would drive out the Jurchen forces east of the Yalu River and secure the region in exchange for establishing diplomatic relations with the Khitan. After receiving the approval of the Khitan emperor, this arrangement was officially recognized. It later provided an important diplomatic foundation for Goryeo’s acquisition of the Six Garrisons East of the River (Gangdong Yukju).

However, contrary to the common perception, the Khitan did not directly hand over the territory of the Six Garrisons to Goryeo. At the time, Jurchen groups occupied the region east of the Yalu River, meaning that Goryeo itself had to secure the territory.

Following the negotiations, Seo Hui led Goryeo forces into the region, drove out the Jurchen groups, and expanded Goryeo’s control toward the Yalu River. Goryeo then established six fortified settlements—Heunghwajin, Yongju, Tongju, Cheolju, Gwiju, and Gwakju—creating a defensive system in the newly secured territory.

Ultimately, Seo Hui’s diplomatic negotiations did more than simply bring the Khitan invasion to an end. They provided Goryeo with an opportunity to expand its territory toward the region east of the Yalu River and secure the Six Garrisons East of the River (Gangdong Yukju). It can be regarded as a representative example of how Goryeo transformed the crisis of war into an opportunity for territorial expansion through diplomatic negotiation and military expansion.

# The Second Khitan Invasion and the Achievements of Yang Gyu

In 1010, Emperor Shengzong of the Khitan Liao dynasty personally led a massive army of 400,000 troops in an invasion of Goryeo.

The Khitan used General Gang Jo’s coup, in which King Mokjong was deposed and King Hyeonjong was placed on the throne, as the justification for the invasion. However, several unresolved issues remained between the two states, including disputes over the Six Garrisons that Goryeo had secured following the first invasion and Goryeo’s relations with the Song dynasty.

The Great Battle of Tongju and Gang Jo’s Defeat

As the Khitan army advanced southward, Goryeo appointed Gang Jo as commander-in-chief and mobilized a large army to confront the invasion.

In the large-scale battle fought around Tongju, 200,000 Khitan troops led by Xiao Paiya clashed with 300,000 Goryeo troops commanded by Gang Jo.

During the early stages of the battle, the Goryeo army established a defensive formation centered on geomcha (劍車, sword carts) and successfully repelled several Khitan attacks.

Unable to break through Goryeo’s defensive lines with frontal assaults, the Khitan army changed its tactics.

Xiao Paiya deployed troops led by Yelü Pennu and Yelü Dilu to launch a surprise attack on the Goryeo camp at Samsu, where the defenses were relatively weak. The attack caused the Goryeo formation to collapse, and eventually even Commander-in-Chief Gang Jo was captured by the Khitan forces.

The Goryeo army suffered enormous losses in the battle, allowing the Khitan forces to seize the initiative and continue their advance southward.

The Khitan army immediately attacked the fortress of Tongju but failed to capture it.

Fierce Fighting over Seogyeong

To defend Seogyeong (present-day Pyongyang), a strategically important stronghold, the Goryeo court mobilized additional troops from the Eastern Frontier (Donggye).

Tak Sa-jeong and Ji Chae-mun arrived with approximately 20,000 reinforcements from the Eastern Frontier. They suppressed the faction of Won Jong-seok, the governor of Seogyeong, who had attempted to surrender to the Khitan, and took control of the city to organize its defenses.

Fierce fighting subsequently broke out between the Goryeo and Khitan forces around Seogyeong.

When Emperor Shengzong of Liao dispatched 200 cavalrymen in an attempt to seize Seogyeong, Goryeo cavalry led by Ji Chae-mun launched a surprise attack against them. According to historical records, 100 Khitan cavalrymen were killed in the engagement, while the remaining 100 were captured.

Another force of 3,000 Khitan cavalry approaching the area was subsequently attacked by the Goryeo forces and reportedly annihilated.

Enraged by these setbacks, Emperor Shengzong of Liao mobilized a large army and launched a full-scale assault on Seogyeong. However, Goryeo forces, including officials and commanders such as Gang Min-cheom and Jo Won, firmly defended the city, preventing the Khitan army from capturing it.

Emperor Shengzong’s Advance on Gaegyeong

Without having fully secured Seogyeong, Emperor Shengzong led his main army southward toward Gaegyeong, the capital of Goryeo.

The Khitan forces eventually entered Gaegyeong, while King Hyeonjong abandoned the capital and fled southward.

However, the situation facing the Khitan army was also becoming increasingly difficult.

The Khitan forces had advanced deep into Goryeo territory without fully securing major strongholds in their rear, including Heunghwajin, Tongju, and Seogyeong. As a result, their supply lines became increasingly stretched, while repeated attacks by Goryeo forces in the rear made the movement of troops and supplies more difficult.

The harsh winter weather and shortages of food further complicated the situation, making it increasingly difficult for the Khitan army to continue a prolonged military campaign.

Moreover, King Hyeonjong had already fled far to the south, making it virtually impossible for the Khitan to capture the Goryeo king. Emperor Shengzong therefore decided to abandon any further southward advance and withdraw his forces back to Liao territory.

For the Khitan army, however, the withdrawal marked the beginning of another battle.

Yang Gyu’s Counterattack and the Recapture of Gwakju Fortress

Meanwhile, in the rear of the Khitan army, Goryeo forces led by Yang Gyu continued to launch counterattacks.

After successfully defending Heunghwajin against the Khitan assault, Yang Gyu led a relatively small force and began a series of aggressive counteroffensive operations.

Most notably, Yang Gyu led approximately 1,700 troops in a surprise attack on Gwakju Fortress, which was being used as a rear base by around 6,000 Khitan soldiers. The Goryeo forces successfully recaptured Gwakju Fortress and annihilated the Khitan troops stationed there.

The recapture of Gwakju Fortress meant far more than simply recovering a single stronghold. By threatening the rear of the Khitan army, which had advanced deep into Goryeo territory, it made both the supply and withdrawal of the Khitan forces increasingly difficult.

Yang Gyu and Kim Suk-heung’s Pursuit of the Retreating Khitan Army

According to historical records, Goryeo forces led by Yang Gyu and Kim Suk-heung defeated at least 16,500 Khitan troops in a series of battles over the course of approximately one month.

Their major victories can be summarized as follows:

(1) Battle of Murodae

Goryeo forces led by Yang Gyu defeated approximately 2,000 Khitan troops and rescued Goryeo civilians who were being taken away as captives.

(2) Battle of Isu

The Goryeo forces attacked and defeated the Khitan army, once again rescuing many Goryeo captives.

(3) Battle of Seongnyeong

Goryeo forces led by Yang Gyu and Kim Suk-heung attacked the Khitan army and reportedly killed approximately 2,500 enemy troops.

(4) Battle of Yeoricham

The Goryeo forces pursued the retreating Khitan army and killed approximately 1,000 enemy soldiers.

(5) Battle of Aejeon (The Final Battle)

Yang Gyu and Kim Suk-heung launched a surprise attack on the vanguard of the retreating Khitan army, killing approximately 1,000 enemy troops. However, they subsequently encountered the large main force commanded by the Khitan emperor himself. Despite being overwhelmingly outnumbered, the two generals refused to retreat and continued fighting until they had exhausted all their arrows. In the end, both Yang Gyu and Kim Suk-heung were killed in battle.

For approximately one month, the Goryeo forces led by Yang Gyu and Kim Suk-heung relentlessly attacked the Khitan army, threatening its supply lines and routes of retreat. They also achieved the remarkable feat of rescuing approximately 30,000 Goryeo civilians who had been captured and were being taken away by the Khitan forces.

The Consequences of the Second Khitan Invasion

The Khitan army succeeded in defeating Goryeo’s main forces at Tongju and even occupying the capital, Gaegyeong. On the surface, this might appear to have been an overwhelming Khitan victory.

However, the Khitan forces failed to fully secure Goryeo’s major defensive strongholds, including Heunghwajin, Tongju, and Seogyeong. As a result, the rear and supply lines of the Khitan army, which had advanced deep into Goryeo territory, remained under constant threat.

Moreover, Goryeo forces led by commanders such as Yang Gyu and Kim Suk-heung continuously attacked the retreating Khitan army, inflicting significant casualties and rescuing large numbers of Goryeo civilians who had been taken captive.

Ultimately, despite occupying the capital of Gaegyeong, the Khitan were forced to withdraw without destroying the Goryeo dynasty or completely subjugating the kingdom.

Therefore, the Second Khitan Invasion can be regarded as a war in which the Khitan army defeated Goryeo’s main field army and occupied its capital, yet failed to fully achieve its strategic objectives due to continued resistance centered on Goryeo’s major fortresses and persistent attacks against the Khitan rear.

# The Third Khitan Invasion and the Great Battle of Gwiju

In the winter of 1018, after Goryeo failed to fulfill its promise to pay homage at the Liao court, the Khitan once again dispatched an army of 100,000 troops under the command of Xiao Paiya to invade Goryeo.

Goryeo prepared a large-scale defensive campaign under the leadership of Gang Gam-chan.

Gang Gam-chan sought to slow the Khitan advance while disrupting their supply lines and waiting for the exhausted enemy forces to begin their withdrawal.

The Khitan army suffered heavy losses as Goryeo forces repeatedly intercepted its advance. At the battles of Heunghwajin, Jaju, and Matan, Goryeo troops killed large numbers of Khitan soldiers.

Undeterred by these setbacks, Xiao Paiya continued his rapid advance southward toward the capital, Gaegyeong. Unlike during the previous invasion, however, Gaegyeong was now heavily fortified and well prepared for defense.

To make matters worse, at the Battle of Geumgyoyeok, 300 Khitan cavalry scouts were annihilated by an attack from 100 cavalrymen of Goryeo’s central army.

Realizing that there was little chance of achieving victory, Xiao Paiya ultimately decided to withdraw his forces.

Goryeo forces continued to attack Xiao Paiya’s Khitan army as it retreated. At the battles of Yeonju and Wiju, Goryeo troops lay in wait along the Khitan army’s route and launched a surprise attack, killing 500 Khitan soldiers in a short period of time.

The Goryeo army then encountered the main body of the retreating Khitan forces on the plains of Gwiju and engaged them in a direct battle on open ground. After several days of fierce fighting had exhausted both armies, 10,000 cavalrymen from Goryeo’s central army, led by Kim Jong-hyeon and arriving from Gaegyeong, launched a surprise attack against the Khitan rear. The Khitan formation completely collapsed.

The Goryeo army relentlessly pursued the fleeing Khitan forces all the way to the Yalu River. Tens of thousands of Khitan soldiers were killed, including troops from the Cheonun Army (天運軍) and the Right Pishi Army (右皮室軍), elite units of the Liao imperial forces.

Of the original army of 100,000 troops, only a few thousand reportedly returned alive, including the commander-in-chief, Xiao Paiya. Approximately 98,000 Khitan soldiers were killed or captured by the Goryeo forces.

Following this defeat, the Khitan effectively abandoned further large-scale invasions of Goryeo, and relatively stable relations developed between Goryeo and the Liao dynasty.

Goryeo’s international standing subsequently rose significantly, allowing it to emerge as one of the three major powers of Northeast Asia. The kingdom then entered a golden age and enjoyed the height of its national power for approximately a century.

# Strengthening National Defense after the Wars with the Khitan

Through its wars with the Khitan, Goryeo came to recognize the importance of strengthening its northern defense system.

The kingdom constructed an outer defensive wall (Naseong) around Gaegyeong to protect the capital. Later, it built the Cheolli Jangseong (Thousand-Li Wall) along its northern frontier to defend against possible invasions by the Khitan and Jurchens.

Goryeo also began carving the woodblocks for the First Edition of the Tripitaka Koreana (Chojo Daejanggyeong), praying for divine protection against the Khitan invasions.

2. The 12th Century: The Rise of the Jurchens and the Emergence of the Jin Dynasty

After the wars with the Khitan ended, the Jurchens emerged as the next major power that Goryeo had to confront.

For a long time, the Jurchens had lived as various separate tribes throughout Manchuria. However, as they gradually unified and expanded their power, they began to threaten Goryeo’s northeastern frontier.

The Jurchen army, particularly its cavalry forces, possessed formidable military strength.

Jurchen Heavy Cavalry

# Yun Gwan and the Byeolmuban

In its early battles against the Jurchens, the Goryeo army struggled against the powerful Jurchen cavalry.

During the reign of King Sukjong, General Yun Gwan concluded that Goryeo’s existing military organization was not sufficient to effectively counter the Jurchen cavalry and proposed the creation of a new military force.

As a result, the Byeolmuban (別武班), a special military force, was established.

The Byeolmuban was primarily composed of the Singigun, a cavalry force; the Sinbogun, an infantry force; and the Hangmagun, which consisted of Buddhist warrior monks.

# The Expansion into the Northeast and the Nine Fortresses

During the reign of King Yejong, Yun Gwan led a Byeolmuban force of 170,000 troops in a campaign against the Jurchens.

The Goryeo army pushed the Jurchen forces northward and established nine fortresses in the northeastern region. These became known as the Nine Fortresses of the Northeast (Dongbuk Guseong).

However, fierce Jurchen counterattacks made the long-term defense of the newly acquired territory a considerable military and economic burden for Goryeo.

The Jurchens also continued to demand the return of the territory.

Ultimately, after approximately a year of intense fighting, Goryeo returned the Nine Fortresses of the Northeast to the Jurchens.

# The Rise of the Jin Dynasty and Goryeo’s Tributary Relationship

The power of the Jurchens subsequently grew even stronger.

Aguda of the Wanyan clan unified the Jurchen tribes and established the Jin dynasty in 1115. After destroying the Khitan Liao dynasty, Jin expanded its power and placed increasing pressure on the Song dynasty, emerging as a new major power in East Asia.

The Jurchens, who had once sent tribute to Goryeo, had now established a state far more powerful than Goryeo itself.

The Jin dynasty demanded that Goryeo accept a ruler-subject relationship.

The demand sparked debate within the Goryeo court. However, during the reign of King Injong, the faction led by Yi Ja-gyeom, which dominated the government at the time, accepted Jin’s demand in consideration of the realities of the changing international situation.

This foreign policy later became one of the political factors behind the movement led by Myocheong and other members of the Seogyeong faction, who advocated a military campaign against Jin and called for Goryeo’s ruler to assume the title of emperor and proclaim a new era name.

3. The 13th Century: The Mongol Invasions and Goryeo’s Prolonged Resistance

In the 13th century, Goryeo encountered an enemy more powerful than any it had previously faced.

After Genghis Khan unified the Mongol tribes, the Mongol Empire expanded beyond northern China and Central Asia, eventually extending its power across much of Eurasia.

Goryeo could not escape the expansion of the Mongol Empire.

# The Murder of the Mongol Envoy Jeogoye

Goryeo and the Mongols were not hostile toward each other from the beginning.

The two sides temporarily cooperated in the process of defeating the remnants of the Khitan forces.

However, the Mongols gradually began demanding excessive tribute from Goryeo, causing relations between the two sides to deteriorate.

The decisive incident was the murder of the Mongol envoy Jeogoye.

In 1225, Jeogoye, who had visited Goryeo as a Mongol envoy, was killed while returning home. The Mongols held Goryeo responsible for his death.

This incident later became one of the justifications used by the Mongols for their invasion of Goryeo.

# The Mongol Invasions and the Transfer of the Capital to Ganghwa Island

In 1231, the Mongol army launched a full-scale invasion of Goryeo.

At the time, real political power in Goryeo was controlled by the Choe military regime.

Taking advantage of the relative weakness of the Mongol cavalry in naval warfare, the government led by Choe U moved the capital from Gaegyeong to Ganghwa Island in 1232.

From then on, the Goryeo court continued its prolonged resistance against the Mongols from its base on Ganghwa Island.

However, the Mongol invasions caused enormous suffering among the civilian population on the mainland. Mongol forces repeatedly attacked various regions throughout Goryeo, and countless people were killed or taken captive.

# The Battle of Cheoin Fortress and Kim Yun-hu

In 1232, Mongol forces led by the commander Sartaq attacked Cheoin Fortress.

At Cheoin Fortress, local residents, including the Buddhist monk Kim Yun-hu, resisted the Mongol army.

During the battle, the Mongol commander Sartaq was killed, throwing the Mongol forces into confusion and ultimately forcing them to withdraw.

Kim Yun-hu later fought against the Mongol forces in the Chungju region as well. During these battles, local residents, including slaves and members of the lowest social classes, actively participated in the resistance.

The war against the Mongols was a prolonged struggle involving not only the central government’s regular army but also people from various social groups, including local residents, Buddhist monks, slaves, and other members of the lower classes.

# The Destruction of Cultural Heritage and the Tripitaka Koreana

Goryeo’s cultural heritage also suffered extensive damage during the prolonged wars.

During the Mongol invasions, the nine-story wooden pagoda of Hwangnyongsa Temple in Gyeongju was destroyed by fire, while the First Edition of the Tripitaka Koreana (Chojo Daejanggyeong), which had been created during the Khitan invasions, was also lost.

Goryeo sought to overcome the Mongol invasions through the spiritual power of Buddhism and therefore undertook the carving of a new edition of the Buddhist canon.

This became the Palman Daejanggyeong, or the Second Edition of the Tripitaka Koreana, which is preserved today at Haeinsa Temple.

The carving of the Tripitaka Koreana was more than simply a religious undertaking. It was a massive state-sponsored project that embodied the hopes of the Goryeo people to overcome a national crisis.

# The Return to Gaegyeong and the Sambyeolcho Resistance

As the prolonged war imposed a considerable burden on both Goryeo and the Mongols, the two sides gradually entered into negotiations.

In 1259, Goryeo concluded a peace agreement with the Mongols. King Wonjong subsequently strengthened relations with the Mongols and pursued the return of the capital to Gaegyeong.

However, the Sambyeolcho, which had served as an important military foundation of the Choe military regime, opposed both the return to Gaegyeong and Goryeo’s submission to the Mongols.

Led by Bae Jung-son, the Sambyeolcho rose in rebellion on Ganghwa Island and later moved to Jindo, where they continued their resistance.

After Jindo fell, Kim Tong-jeong led the remaining forces to Jeju Island and continued the struggle.

Thus, the route of the Sambyeolcho resistance can be summarized as follows:

Ganghwa Island → Jindo → Jeju Island

In 1273, the suppression of the Sambyeolcho forces on Jeju Island effectively brought nearly 40 years of war and resistance between Goryeo and the Mongols to an end.

Thereafter, Goryeo came under the powerful influence of the Yuan dynasty.

4. The Period of Yuan Intervention and Changes in Goryeo

The end of the war with the Mongols did not mean that Goryeo returned to a state of complete independence.

Goryeo became a son-in-law state of the Yuan dynasty, and Goryeo kings entered into marriage alliances with the Yuan imperial family.

The character Chung (忠), meaning “loyalty,” began to appear in the royal titles of Goryeo kings, as seen in King Chungnyeol, King Chungseon, and King Chungsuk, symbolizing loyalty to the Yuan dynasty.

The Yuan also exercised considerable influence over Goryeo’s domestic affairs and established administrative territories such as the Ssangseong Commandery (Ssangseong Chonggwanbu) and the Dongnyeong Commandery (Dongnyeongbu) in parts of Goryeo territory.

Goryeo was also required to provide troops, ships, and supplies for the Yuan dynasty’s invasions of Japan.

However, the Goryeo dynasty itself did not disappear. Despite strong Yuan interference, Goryeo continued to maintain its own king, bureaucracy, and independent state institutions.

5. The 14th Century: King Gongmin’s Anti-Yuan Policies and the Red Turban Invasions

By the 14th century, the Yuan dynasty had begun to decline.

Rebellions against Yuan rule erupted throughout China, and one of the most prominent rebel forces was the Red Turban Army.

King Gongmin of Goryeo took advantage of these changes in the international situation to free Goryeo from Yuan interference.

King Gongmin removed pro-Yuan forces from power, purged Gi Cheol, and attacked the Yuan-controlled Ssangseong Commandery, recovering some of the territory north of Cheollyeong.

However, as the power of the Yuan dynasty weakened, the growing turmoil on the Chinese mainland began to spread into Goryeo.

# The Red Turban Invasions

The Red Turban Army invaded Goryeo on two separate occasions.

During the large-scale invasion of 1361, the Red Turban forces captured Gaegyeong, the capital of Goryeo.

King Gongmin was forced to abandon the capital and flee south to Bokju, present-day Andong.

The Goryeo army later regrouped its forces, recaptured Gaegyeong, and drove out the Red Turban Army.

During these conflicts, military commanders such as Choe Yeong and Yi Seong-gye distinguished themselves in battle and began to build their military reputations.

6. The Late 14th Century: Large-Scale Wokou Invasions

One of the most serious problems facing Goryeo in its final years was the increasing frequency of Wokou raids.

The Wokou were maritime raiders based in the Japanese archipelago who carried out attacks along the coasts of the Korean Peninsula and China.

In the late 14th century in particular, the range of Wokou activities expanded beyond coastal regions and extended deep into the Korean interior.

Their attacks went far beyond simply plundering coastal villages. Large forces sometimes landed on the Korean Peninsula and attacked major regional cities as well as important grain transportation routes.

As grain transportation came under increasing threat, serious problems also emerged for the economy of the capital, Gaegyeong, and for Goryeo’s state finances.

To counter the Wokou raids, the Goryeo government began actively introducing new weapons and strengthening its military organization.

# Choe Mu-seon and the Battle of Jinpo

One of the most important figures in the fight against the Wokou was Choe Mu-seon.

Choe Mu-seon studied gunpowder manufacturing techniques and laid the foundation for Goryeo to produce its own gunpowder weapons.

In 1377, the Goryeo government established the Hwatong Dogam (Firearms Directorate) and began the large-scale production of gunpowder and firearms.

In 1380, when a large Wokou fleet appeared at Jinpo, the Goryeo navy attacked using warships equipped with gunpowder weapons developed by Choe Mu-seon.

This became known as the Battle of Jinpo.

The Wokou fleet suffered heavy losses from Goryeo’s gunpowder weapons.

The Battle of Jinpo was a landmark engagement in which the Goryeo navy made extensive use of gunpowder weapons to defeat a large Wokou fleet.

# Yi Seong-gye and the Battle of Hwangsan

Many of the Wokou who had lost their ships at Jinpo moved inland and continued their raids.

The Goryeo government dispatched Yi Seong-gye to suppress them.

In 1380, Goryeo forces led by Yi Seong-gye confronted the Wokou at Hwangsan, near Namwon in present-day Jeolla Province.

In this battle, the Goryeo army decisively defeated the main Wokou forces. This victory became known as the Battle of Hwangsan.

Through this victory, Yi Seong-gye further strengthened his reputation as an outstanding military commander.

# Park Wi’s Expedition to Tsushima

Goryeo did not remain solely on the defensive but also launched direct attacks against bases used by the Wokou.

In 1389, during the reign of King Chang, Park Wi led the Goryeo navy in an expedition against Tsushima Island.

The Goryeo forces destroyed Wokou ships and facilities and rescued Goryeo people who had been taken captive.

This demonstrates that Goryeo adopted an active offensive strategy at sea in an effort to deal with the Wokou threat.

7. The Rise of New Military Leaders amid Foreign Invasions

The invasions of the Red Turbans and the Wokou caused enormous damage to Goryeo society, but paradoxically, they also became a catalyst for changes in the political order of late Goryeo.

In the process of defending the kingdom against repeated foreign invasions, a new generation of military leaders emerged who differed from the established aristocratic families and powerful elite clans.

The most prominent figures among them were Choe Yeong and Yi Seong-gye.

By defeating the Red Turbans and the Wokou, they gained considerable military prestige and established their own military power bases.

Yi Seong-gye, in particular, possessed a strong military base in the northeastern frontier region and rose to become one of Goryeo’s leading generals through victories in numerous battles, including the Battle of Hwangsan.

Later, when the Ming dynasty attempted to establish the Cheollyeong Guard in the territory north of Cheollyeong, the Goryeo court decided to launch a military expedition against Liaodong.

Yi Seong-gye opposed the Liaodong campaign, presenting his Four Reasons Against the Expedition (Four Impossibilities, 四不可論), but King U and Choe Yeong insisted on proceeding with the campaign.

In 1388, Yi Seong-gye led the army northward for the planned expedition against Liaodong, but upon reaching Wihwa Island on the Yalu River, he turned his forces back.

This event became known as the Wihwa Island Retreat.

Following this incident, Yi Seong-gye and the radical faction of the Sinjin Sadaebu (new scholar-officials) seized political power, and the Goryeo dynasty rapidly entered the path toward its collapse.

The Overall Course of Goryeo’s Foreign Relations

The broad course of Goryeo’s foreign relations over nearly 500 years can be summarized as follows:

# 10th–11th Centuries

Conflict with the Khitan Liao dynasty

→ Seo Hui’s acquisition of the Six Garrisons East of the River

→ Yang Gyu’s resistance

→ Gang Gam-chan’s victory at the Great Battle of Gwiju

# 12th Century

Rise of the Jurchens

→ Yun Gwan’s organization of the Byeolmuban

→ Establishment of the Nine Fortresses of the Northeast

→ Establishment of the Jin dynasty by the Jurchens

→ Goryeo’s acceptance of a tributary relationship with Jin

# 13th Century

Expansion of the Mongol Empire

→ Mongol invasions of Goryeo

→ Transfer of the capital to Ganghwa Island

→ Battle of Cheoin Fortress

→ Carving of the Tripitaka Koreana

→ Peace agreement between Goryeo and the Mongols

→ Return of the capital to Gaegyeong

→ Sambyeolcho resistance

# 13th–14th Centuries

Yuan intervention in Goryeo

→ Royal marriage alliances

→ Expansion of Yuan political and military influence

# Mid-14th Century

Decline of the Yuan dynasty

→ King Gongmin’s anti-Yuan policies

→ Red Turban invasions of Goryeo

→ Fall of Gaegyeong and the royal court’s evacuation to Bokju

# Late 14th Century

Intensification of Wokou raids

→ Choe Mu-seon’s victory at the Battle of Jinpo

→ Yi Seong-gye’s victory at the Battle of Hwangsan

→ Park Wi’s expedition to Tsushima

→ Rise of new military leaders

→ Wihwa Island Retreat and the decline of the Goryeo dynasty

Conclusion: How Foreign Invasions Changed the Fate of Goryeo

The history of Goryeo’s foreign relations was also a history of adapting to changes in the international order of East Asia.

During the early Goryeo period, the kingdom successfully resisted the Khitan invasions and even secured the Six Garrisons East of the River. When the Jurchens grew stronger, Goryeo pursued an active northern policy by organizing the Byeolmuban and establishing the Nine Fortresses of the Northeast.

However, the emergence of the Mongol Empire in the 13th century completely transformed the international environment that Goryeo had previously experienced.

Goryeo resisted the Mongols for approximately three decades and succeeded in preserving its dynasty. After the war ended, however, the kingdom remained under the powerful political influence of the Yuan dynasty for an extended period.

In the 14th century, the international order once again changed dramatically. As the Yuan dynasty declined and the Ming dynasty emerged, the Red Turban forces became active in China, while Wokou raids increased sharply in the south.

Goryeo succeeded in defeating both the Red Turbans and the Wokou, but decades of warfare severely destabilized the kingdom’s existing political order.

In particular, military commanders such as Choe Yeong and Yi Seong-gye rose to the center of politics after building their reputations in wars against foreign enemies. Ultimately, the dispute over the Liaodong expedition arising from relations with the Ming dynasty led to the Wihwa Island Retreat of 1388. After gaining control of the military, Yi Seong-gye and the radical Sinjin Sadaebu dismantled Goryeo’s existing power structure.

Therefore, when examining Goryeo’s foreign relations, it is important not merely to view them as a sequence of invasions—Khitan → Jurchen → Mongol → Red Turbans and Wokou—but also to consider the broader shifts in East Asian regional power that lay behind them.

Khitan Liao → Jurchen Jin → Mongol Yuan → Decline of Yuan and Rise of Ming

Amid these changes in the international order, Goryeo preserved its dynasty for nearly 500 years through a combination of diplomacy and warfare. By the late Goryeo period, however, the new military forces that had risen while defending the kingdom against foreign threats began to reshape the existing political order. This transformation ultimately led to the end of the Goryeo dynasty and the founding of the Joseon dynasty.