The Ashina (; Middle Chinese: (Guangyun) ) were a Turkic speaking tribe and the ruling dynasty of the Göktürks. This clan rose to prominence in the mid-6th century when the leader, Bumin Qaghan, revolted against the Rouran Khaganate. The two main branches of the family, one descended from Bumin and the other from his brother Istämi, ruled over the eastern and western parts of the Göktürk confederation, respectively. Origin Primary Chinese sources ascribed different origins to the Ashina tribe. Ashina were first attested to 439, as reported by the Book of Sui: on the 18th day of the 10th month, the Tuoba ruler Emperor Taiwu of Northern Wei overthrew Juqu Mujian of the Northern Liang in eastern Gansu, and 500 Ashina families fled northwest to the Rouran Khaganate near Gaochang. According to the Book of Zhou, History of the Northern Dynasties, and New Book of Tang, the Ashina clan was a component of the Xiongnu confederation. but this is contested. Göktürks were also posited as having originated from an obscure Suo state (索國), north of the Xiongnu. According to the Book of Sui and the Tongdian, they were "mixed barbarians" (; záhú) from Pingliang. According to some researchers (Duan, Xue, Tang, and Lung) the Ashina tribe was descended from the Tiele confederation, who were likewise associated with the Xiongnu. Like the Göktürks, the Tiele were probably one of many nomadic Turkic peoples on the steppe. However, Lee & Kuang (2017) state that Chinese histories did not describe the Ashina-led Göktürks as descending from the Dingling or belonging to the Tiele confederation. Etymology Several researchers, including Peter B. Golden, H. W. Haussig, S. G. Klyashtorny, Carter V. Findley, D. G. Savinov, B. A. Muratov, S. P. Guschin, and András Róna-Tas have posited that the term Ashina ultimately descends from an Indo-European source, possibly Tocharian or from one of the many Eastern Iranian tribal groups, such as the Saka and Wusun. Carter V. Findley assumes that the name "Ashina" comes from one of the Saka languages of central Asia and means "blue" (which translates to Proto-Turkic *kȫk, whence Old Turkic 𐰚𐰇𐰚‎ kök, and same in all Modern Turkic languages). The color blue is identified with the east, so that Göktürk, another name for the Turkic empire, meant the "Turks of the East"; meanwhile, Peter Benjamin Golden favours a more limited denotation of Göktürks as denoting only the Eastern Turks. This idea is