Eulji Mundeok - The Battle of Salsu River

The Battle of Salsu River

After the founding of the Sui dynasty in 589, a precarious peace obtained for several years between the new Chinese dynasty and Goguryeo. In 597, however, the Goguryeo King Yeongyang launched raids across the Liao River, which is the traditional border with China. In response, the Sui invaded Goguryeo, but the invasion failed as the invasion force was scattered by a typhoon.

In the early 7th century, however, the new Sui emperor Yangdi learned of secret Goguryeo correspondence with the Eastern Turkish khanate. Yangdi took a hard stand and demanded the King Yeongyang come and submit personally to Sui or face an "imperial tour of his territories". When the King Yeongyang failed to submit in this fashion, Yangdi prepared for war. He mustered an army of over 1,133,800 troops and more than 2 million auxiliaries and personally led them against Goguryeo in 612. They quickly overran Goguryeo's border defenses, camped on the banks of the Liao River and prepared to bridge it. Eulji Mundeok, commissioned as a Field Marshal, was called upon to assist in the defence of the nation, and prepared his troops to meet the superior Sui forces with a strategy of false retreat, deception and attack.

After the Sui forces crossed the Liao River, a small contingent was sent to attack the Goguryeo city of Yodong, but Field Marshal Eulji sent Admiral Gang Yi-sik and his forces to meet them there and drove them out. As the rainy season progressed, the Sui forces launched other small probing attacks, but held off from making any large moves before the end of the rainy season.

When the rains stopped, Yangdi moved his forces to the banks of the Yalu River in northwestern Korea and prepared for a major battle. Fighting only small engagements at times and places of his choosing, he drew the Sui forces further and further from their supply centers. A Sui advance force of over 305,000 men was sent to take the city of Pyongyang. After allowing the force to approach the city, Field Marshal Eulji ambushed it. His forces attacked from all sides, driving the Sui troops back in utter confusion. His troops pursued the retreating army, slaughtering them at will; records claim that only 2,700 men of the massive force returned alive to the main Chinese army. This battle, the Battle of Salsu, came known as one of the most glorious military triumphs in Korea's national history. (It was said that Eulji had built a large dam upon the Salsu river which made the waterbed shallow, and as the Sui troops crossed the dam was broken down, releasing a huge current of water upon the unsuspecting troops, thus wiping out nearly the entire fleet with one blow). After the battle, winter began to set in and the Sui forces, short on provisions, were forced to return home.