Northern Wei takes Guzang and unites northern China

The Tuoba, a Xianbei clan whose state of Dai the Former Qin had destroyed in 376, regained their independence after Fu Jian’s defeat on the Fei River: in 386 Tuoba Gui restored the state, soon renamed it Wei, and in 398 made Pingcheng (modern Datong) his capital. His grandson Tuoba Tao, Emperor Taiwu, made it the dominant power of the north. He took Tongwan, the capital of the Xia, in 427 and held the whole Xia realm by 431; in 436 he destroyed the Northern Yan, whose ruler Feng Hong fled to Goguryeo; and he fought the Rouran on the steppe.

The last independent state of the north was the Northern Liang of the Juqu clan in the Hexi Corridor, a rich province on the Silk Road and a centre of Buddhist learning; its ruler Juqu Mujian had married Taiwu’s sister, and his own sister was one of Taiwu’s consorts. In the summer of 439 Taiwu marched west with his main army, leaving 20,000 men to guard the steppe frontier against the Rouran. He reached Guzang (modern Wuwei) on 29 August; on 18 October, after one of Mujian’s nephews had gone over to him with his men, Mujian came out to the gate of the Wei camp with 5,000 officials and soldiers, his hands bound. The emperor untied him and received him as a vassal king. The Book of Wei counts a population of more than 200,000 taken in the city and treasure “beyond counting”. While the emperor was away, the Rouran broke through the frontier as far as the Qijie mountains, and the capital was alarmed.

Taiwu set out for home in November, deporting more than 30,000 households from Liangzhou to Pingcheng; with them, says the Book of Wei, monks and all Buddhist activity moved east, and “the teaching of images” grew greatly in the capital. Members of the Juqu family retreated west and in 442 took Gaochang in the Turfan oasis, which they ruled until 460; Mujian himself died in 447. The fall of Guzang ended the Sixteen Kingdoms period (304–439), which had begun with the collapse of Jin rule in the north. Half a century later Emperor Xiaowen moved the Northern Wei capital to Luoyang (494) and adopted Chinese ways, and the northern states that succeeded the Wei eventually reunited China under the Sui in 589.