Korean History › Three Kingdoms › Goguryeo
Battle of Salsu River under Eulji Mundeok
612 (Sui troop numbers debated)· Battle· Wars & invasions
Mostly agreedGood evidence; some details, dates or numbers uncertain.
In 612 Goguryeo general Eulji Mundeok lured a huge Sui Chinese army deep into Korea, then destroyed it at the Salsu River.
See it on the Korean History map →What happened
Sui Emperor Yang invaded Goguryeo in 612 with an army Sui records put at over 1.1 million soldiers. When the main force stalled at Liaodong fortress, he sent about 305,000 men toward Pyongyang. In the Battle of Salsu (살수대첩), Eulji Mundeok feigned surrender, harassed them as food ran short, and sent their general a mocking poem. As the exhausted Sui troops retreated across the Salsu River, usually identified as the Cheongcheon, he struck. Sui records say only 2,700 returned.
Why it matters
It became Korea's classic victory against a giant, and the costly failed wars helped bring down the Sui dynasty in 618.
How we know
The Chinese Book of Sui and the Samguk sagi agree on the outline; the Samguk sagi preserves Eulji Mundeok's poem, one of the oldest surviving Korean poems.
Still debated
Sui troop totals may be inflated. The popular story that Goguryeo dammed the river and released a flood appears only in much later tradition.
Connections (2)
▸Battle of Salsu River under Eulji Mundeok defended GoguryeoWell documented
The connection
By destroying the Sui strike force sent toward Pyongyang, Salsu wrecked Emperor Yang's 612 invasion. Goguryeo also outlasted Sui attacks in 598, 613 and 614; the drain of men and money fed revolts that toppled Sui in 618.
When and how
612, at the Salsu River in northwestern Korea, with Eulji Mundeok commanding against the Sui generals Yuwen Shu and Yu Zhongwen.
How we know
The Book of Sui admits the disaster and the return of only a few thousand men; the Samguk sagi gives the Goguryeo side.
Debates and open questions
The real army sizes, and whether the Salsu was the Cheongcheon River or another stream, are debated.
▸Battle of Salsu River under Eulji Mundeok foreshadowed Tang's own failure at Siege of Ansi FortressMostly agreed
The connection
Sui's disaster at Salsu showed that huge Chinese armies struggled with long supply lines, short campaign seasons and Goguryeo's fortress defense. Tang, which replaced Sui in 618, met the same problems at Ansi in 645: stalled before walls, it had to retreat before winter.
When and how
Thirty-three years apart: Salsu in 612 under Sui's Emperor Yang, Ansi in 645 under Tang's Emperor Taizong, who had watched Sui collapse.
How sure are we?
This is an interpretive link. Both campaigns are well recorded, and Chinese accounts of each describe the same supply and seasonal problems.
Debates and open questions
Whether Goguryeo's defensive skill or China's logistical limits mattered more is debated.