Pulleyblank cites Paul Pelliot that the Donghu, Xianbei, and Wuhuan were "proto-Mongols".The Eastern Hu, mentioned in the "Shih-chi" along with the Woods Hu and the Lou-fan as barbarians to the north of Chao in the fourth century B.C., appear again as one of the first peoples whom the Hsiung-nu conquered in establishing their empire. Toward the end of the Former Han, as the Hsiung-nu empire was weakening through internal dissension, the Eastern Hu became rebellious. From then on they played an increasingly prominent role in Chinese frontier strategy as a force to play off against the Hsiung-nu. Two major divisions are distinguished, the Hsien-pei to the north and the Wu-huan to the south. By the end of the first century B.C. these more specific names had supplanted the older generic term.