Xiongnu
In the 1920s, Pyotr Kozlov's excavations of the royal tombs at the Noin-Ula burial site in northern Mongolia that date to around the first century CE provided a glimpse into the lost world of the Xiongnu. Other archaeological sites have been unearthed in Inner Mongolia and elsewhere; they represent the Neolithic and historical periods of the Xiongnu's history. Those included the Ordos culture, many of them had been identified as the Xiongnu cultures. The region was occupied predominantly by peoples showing Mongoloid features, known from their skeletal remains and artifacts. Portraits found in the Noin-Ula excavations demonstrate other cultural evidences and influences, showing that Chinese and Xiongnu art have influenced each other mutually. Some of these embroidered portraits in the Noin-Ula kurgans also depict the Xiongnu with long braided hair with wide ribbons, which is seen to be identical with the Ashina clan hair-style. Well-preserved bodies in Xiongnu and pre-Xiongnu tombs in the Mongolian Republic and southern Siberia show both Mongoloid and Caucasian features. Analysis of skeletal remains from sites attributed to the Xiongnu provides an identification of dolichocephalic Mongoloid, ethnically distinct from neighboring populations in present-day Mongolia. Russian and Chinese anthropological and craniofacial studies show that the Xiongnu were physically very heterogenous, with six different population clusters showing different degrees of Mongoloid and Caucasoid physical traits. These clusters point to significant cross-regional migrations (both east to west and west to east) that likely started in the Neolithic period and continued to the medieval Mongolian period.
Xirong
The Xirong together with the eastern Dongyi, northern Beidi, and southern Nanman were collectively called the "Sìyí" (). The "Liji" "Record of Rites" details ancient stereotypes about them.
The people of those five regions – the Middle states, and the [Rong], [Yi], (and other wild tribes round them) – had all their several natures, which they could not be made to alter. The tribes on the east were called [Yi]. They had their hair unbound, and tattooed their bodies. Some of them ate their food without its being cooked. Those on the south were called Man. They tattooed their foreheads, and had their feet turned in towards each other. Some of them (also) ate their food without its being cooked. Those on the west were called [Rong]. They had their hair unbound, and wore skins. Some of them did not eat grain-food. Those on the north were called [Di]. They wore skins of animals and birds, and dwelt in caves. Some of them also did not eat grain-food. The people of the Middle states, and of those [Yi], Man, [Rong], and [Di], all had their dwellings, where they lived at ease; their flavours which they preferred; the clothes suitable for them; their proper implements for use; and their vessels which they prepared in abundance. In those five regions, the languages of the people were not mutually intelligible, and their likings and desires were different. To make what was in their minds apprehended, and to communicate their likings and desires, (there were officers) – in the east, called transmitters; in the south, representationists; in the west, [Di-dis]; and in the north, interpreters. [The term 狄鞮 "didi" ("ti-ti") is identified as: “("anc.") Interpreter of the Di, barbarians of the west.” Translated and adapted from the French.]