Battle of the Salsu River

Timeline

1. 612Liaodong Fortress · LiaoningEmperor Yang of Sui personally led a million-strong army eastward, advancing by land and water. The vanguard had already reached the Goguryeo heartland, and the right guard general Yu Wenzhen led the fleet upriver, approaching Pyongyang.
2. 612Salsu River · KoreaThe famous Goguryeo general Ulji Mundok sent envoys to offer surrender, promising to yield cities, lulling the Sui army's vigilance and deliberately showing weakness to draw the Sui army in pursuit to the banks of the Salsu River.
3. 612Salsu River · KoreaAs the Sui army was halfway across the Salsu River, Ulji Mundok led forces in a surprise attack from high ground on both banks. The Sui army could not support front or rear; many soldiers drowned in the river, corpses choked the channel, and tens of thousands fell in battle.
4. 612–613Liaodong · LiaoningAfter the disaster at the Salsu River, Sui morale collapsed and Emperor Yang was forced to withdraw. The third eastern campaign ended in failure, draining the nation's strength and planting the seeds for the Sui dynasty's rapid fall.