Han dynasty
To the north of China proper, the nomadic Xiongnu chieftain Modu Chanyu (r. 209–174 BC) conquered various tribes inhabiting the eastern portion of the Eurasian Steppe. By the end of his reign, he controlled Manchuria, Mongolia, and the Tarim Basin, subjugating over twenty states east of Samarkand. Emperor Gaozu was troubled about the abundant Han-manufactured iron weapons traded to the Xiongnu along the northern borders, and he established a trade embargo against the group. In retaliation, the Xiongnu invaded what is now Shanxi province, where they defeated the Han forces at Baideng in 200 BC. After negotiations, the "heqin" agreement in 198 BC nominally held the leaders of the Xiongnu and the Han as equal partners in a royal marriage alliance, but the Han were forced to send large amounts of tribute items such as silk clothes, food, and wine to the Xiongnu.
Xiongnu
Over the past decade, Chinese archaeologists have published several reviews regarding the results of excavations in Xinjiang. They imply the Xiongnu's supreme ruling class. Particularly interesting are the tombs in the cemetery at Heigouliang, Xinjiang (the Black Gouliang cemetery, also known as the summer palace of the Xiongnu king), east of the Barkol basin, near the city of Hami. By typing results of DNA samples during the excavation of one of the tombs, it was determined that of the 12 men: 6 Q1a* (not Q1a1-M120, not Q1a1b-M25, not Q1a2-M3), 4 Q1b-M378, 2 Q* (not Q1a, not Q1b: unable to determine subclades):