The Göktürks or Kök Türks (Old Turkic: Türük or Kök Türük or Türük;Celestial Turks) were a nomadic confederation of Turkic peoples in medieval Inner Asia. Known in Chinese sources as 突厥 (Modern Chinese: Pinyin: Tūjué, Wade-Giles: T'u-chüeh, Middle Chinese (Guangyun): dʰuət-kĭwɐt), the Göktürks under the leadership of Bumin Qaghan (d. 552) and his sons succeeded the Rouran as the main power in the region and took hold of the lucrative Silk Road trade. Gök means "sky" in modern Turkish.
The Göktürks became the new leading element amongst the disparate steppe peoples in Central Asia, after they rebelled against the Rouran Khaganate. Under their leadership, the Turkic Khaganate rapidly expanded to rule huge territories in Central Asia. From 552 to 745, Göktürk leadership bound together the nomadic Turkic tribes into an empire, which eventually collapsed due to a series of dynastic conflicts.[citation needed]
According to Chinese sources, the meaning of the word Tūjué was "combat helmet" (兜鍪; Pinyin: dōumóu, Wade-Giles: tou-mou), reportedly because the shape of the Jinshan (金山 jīnshān, Altai Mountains), where they lived, was similar to a combat helmet - hence they called themselves 突厥 (Tūjué / T'u-chüeh).