遼史
By the time the "Book of Wei" was written in 554, the Khitans had formed a state in what is now China's Jilin and Liaoning Provinces. The Khitans suffered a series of military defeats to other nomadic groups in the region, as well as to the Chinese Northern Qi (550–577) and Sui (589–618) dynasties. Khitan tribes at various times fell under the influence of Turkic tribes such as the Uighurs and Chinese dynasties such as the Sui and Tang. In the "Book of Sui" (Volume 84), the Khitan are described as "bellicose in plundering and raiding borders" and "the most uncourteous and arrogant among all barbarians". The "History of Liao" (LS, vol. 32 and 59) gives the following account of the early Khitan: