History of Mongolia
Although the Xiongnu finally had been split into two parts in AD 48, the Xianbei (or Hsien-pei in Wade–Giles) had moved (apparently from the east) into the region vacated by the Xiongnu. The Xianbei were the northern branch of the Donghu (or Tung Hu, the Eastern Hu), a proto-Mongol group mentioned in Chinese histories as existing as early as the 4th century BC. The language of the Donghu is believed to be proto-Mongolic to modern scholars. The Donghu were among the first peoples conquered by the Xiongnu. Once the Xiongnu state weakened, however, the Donghu rebelled. By the 1st century AD, two major subdivisions of the Donghu had developed: the proto-Mongolic Xianbei in the north and the Wuhuan in the south.
History of Tuva
The Xiongnu ruled over the area of Tuva prior to 200 AD. The identity of the ethnic core of Xiongnu has been a subject of varied hypotheses and proposals by scholars including Mongolic and Turkic. At this time a people known to the Chinese as Dingling inhabited the region. The Chinese recorded the existence of a tribe of Dingling origin named "Dubo" in the eastern Sayans. This name is recognized as being associated with the Tuvan people and is the earliest written record of them. The Xianbei defeated the Xiongnu and they in turn were defeated by the Rouran. From around the end of the 6th century, the Göktürks held dominion over Tuva up until the 8th century when the Uyghurs took over.