The Liao Dynasty (T: 遼朝 S: 辽朝 pinyin: Liáo Cháo), 907-1125, sometimes also known as the Kingdom or Empire of the Khitan, was founded by the Yelü (耶律 Yēlǜ) family of the Khitan tribes in the final years of the Tang Dynasty, although Yelü Abaoji did not declare an era name until 916. Originally known as the Empire of the Khitan, Emperor Yelü Ruan officially adopted the name Great Liao or Liao Dynasty in 947.
The name of the empire was Khitan between 907 (at its founding) and 947 (938?), and again between 983 and 1066.
It was anniliated by the Jin Dynasty in 1125. However, remnants led by Yelü Dashi (耶律大石 pinyin: Yēlǜ Dŕshí, Wade-Giles: Yeh-lü Ta-Shih) established Xi (Western) Liao Dynasty1125-1220, also known as Kara-Khitan Khanate, which survived until the arrival of Genghis Khan's Mongolian cavalry.
Their military strategy were not any more simple raids on the peasant villages of northern China, but a conquest war with an armoured cavalry.
In 1120, the Song government established an alliance with the Jin empire ĂŠÂÂ in Manchuria to attack the Liao empire.
They brought Chinese customs with them, and the high amount of Nestorian believers among them was the origin of the tale of the king-priest John in Inner Asia.
Since the Khitan had no written script until the eleventh century, we have to rely primarily upon Chinese records of their early history, which are quite scant prior to the seventh century, though the earliest mention of their existence dates to the fourth century.
Khitan leaders also apparently made the observation that to become sedentary themselves would mean that they would have to compete with the Chinese on their terms, something in which the Khitan would have no hope of success.
The Khitan were also in contact with Japan and the Abassid empire, and the court of Baghdad once asked for a Khitan princess for marriage.