Yanmen

Yanmen, the Wild Goose Gate, was the commandery that held the pass through the Gouzhu range in northern Shanxi. A steppe army coming south leaves the grass and enters the Chinese plain at this point. For that reason the Chinese chapters on the Göktürks keep returning to it.

The siege of 615

In the eighth month of 615 the Sui emperor was at the Fenyang palace, out of the heat. Shibi Khan brought his tribes down and shut him inside the town.^[1] The commanderies were ordered to send troops to the imperial camp. The relief armies had just come up when Shibi withdrew.^[1] From that year the khaganate sent the Sui no more tribute.^[1]

The Sui Shu closes its account of the Göktürks by naming the place as the turning point of the dynasty’s fall. It says that Emperor Yang handled the Göktürks in the wrong way. As a result there came the encirclement at Yanmen. Then the risings broke out on every side, and from that time the khaganate grew great.^[1] A Chinese history rarely locates the end of a dynasty at a single town.

The Göktürk wars of the early Tang

The place kept its function under the next dynasty. In 621 Ilig Khan came against Yanmen himself with more than ten thousand horse. A frontier warlord joined him with six thousand. The Tang commander Li Da’en drove him off.^[2] The following year Ilig came back with a hundred and fifty thousand horse. He entered by Yanmen and besieged Bingzhou. He plundered deep into the Fen and Lu country and carried off five thousand men and women.^[3]

The Jiu Tang Shu makes the moral explicit through the mouth of a Tang official addressing the fallen Ilig. Yami had fled his own ruined country to the Sui and been restored by them. He and his sons owed a debt for it. But no sooner had Shibi come to the throne than he raised troops and besieged the emperor at Yanmen.^[2] The siege is used as the charge from which the whole later ruin of the Göktürks is derived.^[2]

The pass as a boundary

Yanmen is not a battlefield that happened to be used twice. It is one of a small number of places through which the traffic between the steppe and China had to pass. The frontier wars of the sixth and seventh centuries turn on it, on the Ordos loop and on the crossings of the Yellow River. Turkic Atlas follows the same ground over a longer span under the wars for hegemony in northern China.