In 552–555 the Göktürks replaced the Rouran Khaganate as the dominant power on the Mongolian Plateau, forming the First Turkic Khaganate (552–630). They quickly spread west to the Caspian Sea.
Between 552–555, the Göktürks took over as the leading force on the Mongolian Plateau, establishing the First Turkic Khaganate (552–630). They swiftly expanded westward to the Caspian Sea.