Turkic peoples. According to the Book of Zhou and the History of the Northern Dynasties, the Ashina clan was a component of the Xiongnu confederation, but this connection is disputed, and according to the Book of Sui and the Tongdian, they were "mixed nomads" () from Pingliang. The Ashina and Tiele may have been separate ethnic groups who mixed with the Xiongnu. Indeed, Chinese sources link many nomadic peoples (hu; see Wu Hu) on their northern borders to the Xiongnu, just as Greco-Roman historiographers called Avars and Huns "Scythians". The Greek cognate of Tourkia () was used by the Byzantine emperor and scholar Constantine VII Porphyrogenitus in his book De Administrando Imperio, though in his use, "Turks" always referred to Magyars. Such archaizing was a common literary topos, and implied similar geographic origins and nomadic lifestyle but not direct filiation. Some Uyghurs claimed descent from the Xiongnu (according to Chinese history Weishu, the founder of the Uyghur Khaganate was descended from a Xiongnu ruler), but many contemporary scholars do not consider the modern Uyghurs to be of direct linear descent from the old Uyghur Khaganate because modern Uyghur language and Old Uyghur languages are different. Rather, they consider them to be descendants of a number of people, one of them the ancient Uyghurs. In various kinds of ancient inscriptions on monuments of Munmu of Silla, it is recorded that King Munmu had Xiongnu ancestry. According to several historians, it is possible that there were tribes of Koreanic origin. There are also some Korean researchers that point out that the grave goods of Silla and of the eastern Xiongnu are alike. Language isolate theories Turkologist Gerhard Doerfer has denied any possibility of a relationship between the Xiongnu language and any other known language, even any connection with Turkic or Mongolian. Geographic origins The original geographic location of the Xiongnu is disputed among steppe archaeologists. Since the 1960s, the geographic origin of the Xiongnu has attempted to be traced through an analysis of Early Iron Age burial constructions. No region has been proven to have mortuary practices that clearly match those of the Xiongnu. Archaeology In the 1920s, Pyotr Kozlov's oversaw the excavation of royal tombs at the Noin-Ula burial site in northern Mongolia, dated to around the first century CE. Other Xiongnu sites have been unearthed in Inner Mongolia, such as the Ordos culture. Sinologist Otto Maenchen-Helfen has said that depictions