About 300 AD, a group of Turkic or Mongol people called the Rouran formed a kingdom in Central Asia. They called their leader the Khan. The Rouran included people from a lot of different ethnic groups, but their leaders were Mongols. At first the Rouran controlled the White Huns, a large group living to their west, as well.
In 552 AD, the Chinese Wei and Qi kingdoms decided to get rid of the Rouran and stop their attacks on China. The Chinese teamed up with a Turkish group, the Gokturks, and this alliance destroyed the power of the Rouran. In their place, the Gokturks started their own kingdom, with their own khan. Some of the Rouran’s subjects, the Avars, eventually moved west to Russia to escape the Gokturks.