The Sir Tardush (Xueyantuo) Khaganate (628-646)

The Sir Tardush were one of the Tiele tribes and lived for a long time under the Göktürk khagans. Chinese sources write their name as "Xueyantuo". In 628 their chief Yinan was proclaimed khagan.

When the Eastern Turkic Khaganate fell to a Tang army in 630, a gap opened in the Ötüken lands, and the Sir Tardush filled it: their rule stretched from the Altai to Manchuria.

The Tang first allied with the Sir Tardush, then came to see them as a threat. In 646 Tang troops and the Uyghurs together destroyed the khaganate. Some of the Sir Tardush later joined the revived Göktürks.