Yelü Dashi, the Liao dynasty general who founded the Qara Khitai, defeats the Seljuq and Kara-Khanid forces at the Battle of Qatwan.

Yelü Dashi, courtesy name Zhongde (重德), also known by his temple name as the Emperor Dezong of Western Liao (西遼德宗), was the founder of the Western Liao dynasty. He initially ruled as king from 1124 to 1132, then as emperor and gurkhan from 1132 to 1143. He was also known in Muslim sources as Nūshī Taifū, Qushqin Taifū or Qushqīn, son of Baighū. A member of the imperial Yelü clan, he fled the Liao dynasty in northern China as it was on the verge of destruction by the Jurchen-led Jin dynasty and moved westward into Central Asia where he established a new empire.

The Liao dynasty, also known as the Khitan State, officially the Great Liao, was a Khitan-led imperial dynasty of China and empire ruled by the Yelü clan that existed between 916 and 1125. Founded around the time of the collapse of the Tang dynasty, at its greatest extent it ruled over Northeast China, the Mongolian Plateau, the northern part of the Korean Peninsula, southern portions of the Russian Far East, and the northern tip of the North China Plain.

The Qara Khitai, or Kara Khitai, also known as the Western Liao, officially the Great Liao, was a dynastic regime based in Central Asia ruled by the Yelü clan of the Khitan people. Being a rump state of the Khitan-led Liao dynasty, Western Liao was culturally Sinicized to a large extent, especially among the elites consisting of Liao refugees.

The Seljuk Empire, or the Great Seljuk Empire, was a high medieval, culturally Turco-Persian, Sunni Muslim empire, established and ruled by the Qïnïq branch of Oghuz Turks. The empire spanned a total area of 3.9 million square kilometres from Anatolia and the Levant in the west to the Hindu Kush in the east, and from Central Asia in the north to the Persian Gulf in the south, and it spanned the time period 1037–1308, though Seljuk rule beyond the Anatolian peninsula ended in 1194.