Heng'an

Heng’an, 恒安, was a garrison town on the northern frontier of the Sui and the Tang.^[1] It appears in the Chinese histories three times in connection with the Göktürks: as the scene of a Sui defeat, as the refuge of a warlord who held it with Göktürk backing, and as one of the roads of the Tang offensive of 629.^[2]

The defeat of Han Hong

In 599 the Sui settled Yami Khan inside the frontier and set troops to guard him against Tardush, the khan of the west.^[3] Han Hong, the commander of Daizhou, held Heng’an with ten thousand foot and horse.^[3] Tardush came with a hundred thousand riders. Han Hong’s army was badly beaten.^[3]

The Sui Shu tells the defeat under the first year of Renshou, 601.^[4] Han Hong was beaten by the enemy at Heng’an and reduced to a commoner.^[4] The Bei Shi repeats the sentence.^[5] The Zizhi tongjian has the defeat twice, once under 599 and again under the first month of 601. In the second entry Tardush, by then Bujia Khan, raided the frontier and beat Han Hong at Heng’an.^[6]

Yuan Junzhang’s base (623–627)

In 623 the Göktürks and the warlord Yuan Junzhang took Mayi. Gao Manzheng, who had held it for the Tang, was killed.^[7] Yuan Junzhang then fell back to hold Heng’an.^[8] His followers were Chinese. Many of them left him to go over to the Tang.^[8] He submitted to the Tang himself. The court sent him a gold certificate as its pledge.^[8]

When Ilig Khan sent to win him back, a man of Heng’an named Guo Ziwei argued for the Göktürks.^[8] He said that Heng’an had difficult ground and strong walls. He said that the Göktürks were at the height of their power, and that Yuan Junzhang should lean on them and wait to see how things turned.^[8] Yuan Junzhang seized the Tang envoy and sent him to the Göktürks. He raided with them several times.^[8] In the fifth month of 627, seeing Ilig’s government in disorder, he surrendered to the Tang for good.^[8]

The war of 629–630

In 629 the Tang sent six columns under the command of Li Jing against Ilig, in the offensive that ended the eastern khaganate.^[9] One of them, under Wei Xiaojie, marched out by the Heng’an road.^[10] After the destruction of Ilig’s state in 630, the Tang recovered the lands of Dingxiang and Heng’an and pushed the frontier out to the great desert.^[11] The Cefu yuangui writes the name in that sentence as 常安.^[12]