By the end of the 4th century, the region between the Yangtze and the Gobi, including much of modern Xinjiang, was dominated by the Tuoba.
There are various hypotheses about the language and ethnic links of the Xianbei and the most widely accepted version suggests that the Xianbei were a Mongolic ethnic group and their branches are the ancestors of many Mongolic peoples such as the Rouran, Khitan and Menggu Xibei, who are suggested to be the proto-Mongols.
The Turkic Khaganate installed tuduns, or governors over the Shiwei and collected tribute.