According to the "Book of Zhou" and "History of the Northern Dynasties", the Ashina clan was a component of the Xiongnu confederation, specifically, the Northern Xiongnu tribes or southern Xiongnu "who settled along the northern Chinese frontier", according to Edwin G. Pulleyblank. However, this view is contested. Göktürks were also posited as having originated from an obscure Suo state (索國) (MC: *"sâk") which was situated north of the Xiongnu and had been founded either by Sakas or Xianbei. According to the "Book of Sui" and the "Tongdian", they were "mixed Hu (barbarians)" () from Pingliang (平涼), now in Gansu, Northwest China. Pointing to the Ashina's association with the Northern tribes of the Xiongnu, some researchers (e.g. Duan, Lung, etc.) proposed that Göktürks belonged in particular to the Tiele confederation, likewise Xiongnu-associated, by ancestral lineage.