Battle of the Salsu: Goguryeo destroys a Sui army

Goguryeo, the northernmost of the Korean kingdoms, had resisted Chinese pressure since the Sui first attacked it in 598, and when its king Yeongyang refused to come to court, Emperor Yang prepared a campaign on an unprecedented scale. In the first month of 612 his armies gathered at Zhuo commandery; the Book of Sui counts 1,133,800 soldiers, ‘called two million’, with twice as many men carrying supplies, and says that it took forty days for the last army to set out. The Sui forced the crossing of the Liao River and besieged the fortress of Liaodong, but the emperor had ordered his commanders to report every move and to accept any offer of surrender, and the city held out.

Nine armies — 305,000 men, says the Zizhi tongjian — were sent on towards Pyongyang under Yuwen Shu and Yu Zhongwen. Each soldier carried a hundred days’ rations and his equipment, so heavy that many buried their grain, and by midway food was running out. Eulji Mundeok came into the Sui camp offering a false surrender in order to see its condition; Yu Zhongwen had orders to seize him, but at the urging of the commissioner Liu Shilong let him go. Eulji then drew the pursuers on, fleeing after each clash: Yuwen Shu won seven battles in a day, crossed the Salsu and camped 30 li from Pyongyang. Eulji sent Yu Zhongwen a mocking poem, preserved in the Book of Sui and the Samguk sagi: ‘Your divine plans have fathomed the heavens, your clever reckoning the earth; your victories are many and your merit is great — be content, and stop here.’ Then he offered a second, false submission, and Yuwen Shu, whose men were exhausted, who saw that Pyongyang was strongly fortified and whose supporting fleet under Lai Hu’er had already been beaten near the city, accepted it and turned back. Harried on all sides, the retreating army reached the Salsu on 26 August; when half of it had crossed, Goguryeo troops fell on the rearguard, the general Xin Shixiong was killed, and the whole force broke and fled 450 li to the Yalu in a day and a night. Of the 305,000 men, the chronicles say, only 2,700 returned to Liaodong, and the emperor withdrew the next day.

The numbers of the Chinese histories may be exaggerated, but the defeat was a catastrophe. The campaigns of 613 and 614 also failed, the first interrupted by the rebellion of Yang Xuangan, and the rebellions that followed brought down the Sui. The Salsu is usually identified with the Chongchon River. The story that Eulji Mundeok broke a dam upstream and drowned the crossing army, told as fact in the Russian Wikipedia article, is not found in the Chinese histories or the Samguk sagi; according to the English article, the idea was put forward by the 20th-century nationalist historian Sin Chaeho and modern popular retellings.