Rouran Khaganate
The Rouran Khaganate, also known as Ruanruan or Juan-juan, was a tribal confederation and later state. The Rouran state was undoubtedly multi-ethnic, most of the historical sources state that they were the descendants of the Xiongnu or a collateral branch of the Xiongnu. Some others state that they were descendants of the Donghu or mixed barbarians beyond the northern border of China Proper. The Book of Song and Book of Liang connected Rourans to the earlier Xiongnu while the Book of Wei connected them to Proto-Mongolic Donghu. The Rouran supreme rulers used the title of khagan, a popular title borrowed from the Xianbei.