 Xueyantuo

The Xueyantuo were an ancient Tiele Turkic people and khaganate in central/northern Asia who were at one point vassals of the Gokturks, later aligning with China's Tang Dynasty against the Eastern Gokturks.The Xueyanto homeland is near the Xueyanhe River (薛延河江/偰輦河江, Selenga River), so their tribe's name is Xueyantuo (薛延陀), Chinese Han characters underwent considerable changes according to changes in Chinese dynasties, so the tribe is variously known as Xueyantuo, Xueyanhe, Xienianhe, Selenga, etc.