Khagan (Qaghan) was a title used by the Turkic people of the Middle Ages. The First and Second Turkic Khaganate were empires ruled by the Ashina tribe of the Göktürks that controlled much of Central Asia and the Mongolian Plateau between 552 and 745 and composed of confederated Turkic tribes. In the 6th century, they challenged the power of numerous dynasties in the Central Plains. At the end of the century following a civil war, the khaganate was divided into eastern and western wings. In the second half of the 7th century, both wings were defeated by the Tang dynasty. However, in 682 they regained their independence.