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.
Zhang Qian
Zhang and Ganfu (as well as Zhang's Xiongnu wife and son) were eventually able to escape and, passing Lop Nor and following the northern edge of the Tarim Basin, around the Kunlun Mountains and through small fortified areas in the middle of oases in what is now Xinjiang until they made their way to Dayuan and eventually to the land of the Yuezhi. The Yuezhi were agricultural people who produced strong horses and many unknown crops including alfalfa for animal fodder. However, the Yuezhi were too settled to desire war against the Xiongnu. Zhang spent a year in Yuezhi and the adjacent Bactrian territory, documenting their cultures, lifestyles and economy, before beginning his return trip to China, this time following the southern edge of the Tarim Basin.
On his return trip he was again captured by the Xiongnu who again spared his life because they valued his sense of duty and composure in the face of death. Two years later the Xiongnu leader died and in the midst of chaos and infighting Zhang Qian escaped. Of the original mission of just over a hundred men, only Zhang Qian and Ganfu managed to return to China.