How Did Goryeo Defeat the Khitan at Gwiju in 1019? The Story of Gang Gam-chan

Goryeo defeated the Khitan at Gwiju in 1019 by wearing down an invading Liao army before fighting it: its commander, Gang Gam-chan, damaged the invaders as they crossed a river, cut their supply lines, harassed them all the way to the capital and back, and then attacked the exhausted army near Gwiju as it retreated north. According to one account, only a few thousand Khitan soldiers reached home. What makes the story more surprising is the man in charge: a scholar-official who had passed the civil service exam decades earlier and was 71 years old when he took command.

Goryeo and the Liao: a quick background

Goryeo was the Korean kingdom founded in 918, with its capital at Gaegyeong, modern Kaesong. To the north-west, the Khitan people had built a powerful empire, the Liao dynasty, which ruled much of Manchuria, Mongolia and northern China. The two states fought a series of wars known as the Goryeo–Khitan Wars, and in 1010 a Liao invasion reached the Goryeo capital. During that crisis Gang Gam-chan advised King Hyeonjong to leave the capital rather than surrender, and the king escaped.

In 1018 the Liao attacked again. Xiao Paiya led an army of about 100,000 across the Yalu River.

From exam hall to battlefield

Gang Gam-chan was born in 948 in Geumju, today part of Gwanak District in southern Seoul. His father had served Goryeo's founding king. After his father's death in 964 he travelled around the country, and in 983, at the age of 36, he passed the state civil service examination with the top score.

His career was in government, not in the army. He held posts connected with education and royal documents, and in 1011 he became an academician responsible for drafting royal edicts. In Goryeo, as in many East Asian states, high civil officials could be given military command, but it was still remarkable for a man of his age to lead an army in the field.

The commander at 71

When the 1018 invasion came, Gang argued for fighting and volunteered to command. He was 71. He led a Goryeo army recorded at about 208,000 men. As with most pre-modern army figures, these numbers come from different sources and are best taken as rough estimates.

The stream and the dam at Heunghwajin

Early in the campaign, at Heunghwajin, Goryeo forces blocked a stream and then broke the dam as the Khitan troops were crossing, causing heavy casualties. The tactic is widely retold in Korea, and it shows Gang's preference for using terrain rather than meeting a strong enemy head-on.

Cutting the supply lines

Despite these losses, the Liao army pushed south and approached Gaegyeong. Instead of risking everything in one pitched battle, Gang cut the invaders' supply lines and harassed them constantly. Far from home and short of food, the Liao forces began a hasty retreat to the north.

The Battle of Gwiju

On 10 March 1019, near Gwiju (modern Kusong in North Korea), Gang's army caught the retreating Liao troops and won a complete victory. The Liao commander escaped with only a few survivors. The battle is often described as one of the greatest victories in Korean military history.

Peace afterwards: two readings

After Gwiju the two sides negotiated, and the Liao did not invade Korea again. Historians describe the settlement differently. One account says Goryeo accepted a tributary relationship with the Liao while keeping its territory along the Yalu. Another stresses that Goryeo kept its ties with the Song dynasty and its own reign title, and that the two states made peace as equals in 1022. Both agree that the long war was over.

Legends and legacy

Gang retired in 1020 and died in 1031 at 82. A legend says a star fell toward his house on the day he was born. The place is still called Nakseongdae, "the site of the fallen star", and gives its name to a station on Seoul Subway Line 2. Koreans often name him alongside Eulji Mundeok and Yi Sun-sin as one of the country's great defenders.

Learn with Gang Gam-chan: English phrases about age and experience

Phrase	Meaning	Example
never too old to	age does not stop you	You're never too old to lead.
to step up	to take responsibility when needed	At 71, he stepped up to command.
to play to your strengths	to use what you are good at	He played to his strengths and used the terrain.
to cut off	to stop a supply or connection	He cut off the enemy's supplies.
a turning point	a moment when things change	Gwiju was a turning point in the war.

Try this: Write three English sentences about someone you know who did something new later in life. Use "step up" and "never too old to".