Xiongnu

The Xiongnu () were nomads who lived north of China from about 3rd century BC to 460s AD. Their lands were very infertile, so they tried to attack China many times. As this was very irritating, the first emperor of China (Qin Shi Huang) built the Great Wall of China around 214 to 206 BC to keep them out. Some Han dynasty emperors tried to stop the wars and make friends with them, but they still tried to attack the Chinese borders.
At first, it was believed that they were related to the Huns, and currently many people still believe this. In old times, nomadic tribes often travelled and lived together, even tribes speaking different languages. Around 60 BC, there was a struggle for power, and the Xiongnu broke up into five smaller tribes.
In 202 AD, the leader of the Southern Xiongnu surrendered to Prime Minister Cao Cao of the Han dynasty.
They are part of the Mongolian people now, or some of them have migrated to China for a better life.
The Han dynasty sent unrelated women falsely labeled as princesses and members of the Han imperial family when they were practicing Heqin marriage alliances with the Xiongnu.
The Xiongnu practiced marriage alliances with Han dynasty officers and officials. The older sister of the Chanyu (the Xiongnu ruler) was married to the Xiongnu General Zhao Xin, the Marquis of Xi who was serving the Han dynasty. The daughter of the Qiedihou Chanyu was married to the Han Chinese General Li Ling after he surrendered and defected. The Yenisei Kirghiz Khagans claimed descent from Li Ling. Another Han Chinese General who defected to the Xiongnu was Li Guangli who also married a daughter of the Chanyu. The Han Chinese diplomat Su Wu married a Xiongnu woman given by Li Ling when he was arrested and taken captive. Han Chinese explorer Zhang Qian married a Xiongnu woman and had a child with her when he was taken captive by the Xiongnu. Han Emperor Wu dispatched the Han Chinese explorer Zhang Qian to explore the mysterious kingdoms to the west and to form an alliance with the Yuezhi people in order to combat the Xiongnu. During this time Zhang married a Xiongnu wife, who bore him a son, and gained the trust of the Xiongnu leader.
The Kyrgyz khagans claimed descent from the Chinese general Li Ling, grandson of the famous Han dynasty general Li Guang. Li Ling was captured by the Xiongnu and defected in the first century BCE. And since the Tang royal Li family also claimed descent from Li Guang, the Kirghiz Khagan was therefore recognized as a member of the Tang Imperial family. This relationship soothed the relationship when Kyrgyz khagan Are (阿熱) invaded Uyghur Khaganate and put Qasar Qaghan to the sword. The news brought to Chang'an by Kyrgyz ambassador Zhuwu Hesu (註吾合素).