Emperor Taiwu’s great campaign against the Rouran

From Taiwu’s accession the Rouran raided the Wei almost every year: in 424 Khagan Datan’s horsemen surrounded the young emperor at Yunzhong, and every Wei counter-expedition found the nomads gone north. In the fourth month of 429 Taiwu resolved on a deep strike. Most ministers, the emperor’s nurse, honoured as empress dowager, and the court astrologers opposed it, fearing an attack from the Liu Song in the south, but Cui Hao argued that the Rouran, trusting in distance, scattered to their pastures in summer and could be caught before they gathered again in autumn; Taiwu replied that unless the Rouran were crushed first, the Wei would face enemies on two fronts.

The emperor marched by the eastern road towards the Black Mountain while Changsun Han took the western road, the two columns converging on the khagan’s camp. In the fifth month the army left its baggage at the edge of the desert and, riding with spare horses, fell on the Rouran at the Li River, identified with the Ongi in Mongolia. Datan burned his yurts and fled west, his brother Pili was beaten by Changsun Han, and the Rouran scattered into the mountains and valleys, leaving their herds untended. Following the river westward, Taiwu passed the old camp of the Han general Dou Xian, and his detachments combed the steppe over 5,000 li from east to west and 3,000 li from north to south. The Gaoche tribes turned on their Rouran masters; the Book of Wei counts more than 300,000 households that surrendered and captives, livestock and tents in the millions, and in the eighth month several hundred thousand more Gaoche submitted at Lake Yini.

In the sixth month the emperor reached the Tuyuan River, 3,700 li from his capital Pingcheng, and then Mount Zhuoye, where his generals, fearing an ambush, talked him out of pressing on; in the seventh month he turned back. Deserters afterwards said that the sick Datan had fled with a few hundred men only 180 li away, and Taiwu later heard a foreign merchant from Liangzhou say that two more days’ march would have destroyed the Rouran completely; the Book of Wei says that he deeply regretted it. In the tenth month the surrendered peoples were settled south of the Gobi over 3,000 li, from the source of the Ru River to Wuyuan and the Yin Mountains, to farm, herd and pay tribute, and so many animals had been taken, the Zizhi tongjian adds, that horses, cattle, sheep and felt became cheap in the Wei lands. Datan died of illness the same year; his son made peace and in 434 married a Wei princess, but in 436 the war resumed.