Yelü Dashi

Yelü Dashi (Chinese: 耶律大石; pinyin: Yēlǜ Dàshí; Wade–Giles: Yeh-Lü Ta-Shih; alternatively Chinese: 耶律達實; pinyin: Yēlǜ Dáshí), 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 (Qara Khitai).

The History of Liao describes him as "well-versed in Khitan and Chinese scripts, excelled in riding and archery, and had passed the highest imperial examination in the fifth year of the Tianqing era" (1115 AD).

It was an old Liao garrison with 20,000 tribal horsemen, good pasture, and protected by desert to the east and south.

After some minor fighting with the Yenisei Kyrgyz [9] he established a new base on the Emil River just east of the current Chinese border about 1500 km west of Kedun.

At about the same time, he was welcomed by the ruler of the Kingdom of Qocho (about 500 km southeast of Emil near Turfan) who became his ally or vassal.

The Eastern Karakanid ruler of Balasaghun, Ibrāhīm II b. Ahmad, invited him to help fight the Karluks and Kankalis, and in 1134 Dashi took the opportunity to depose him, and according to Persian historian Ata-Malik Juvayni, "ascended a throne that had cost him nothing.

In May 1137 he defeated a Western Karakhanid ruler at Khujand and then spent several years consolidating his power in the Ferghana valley and Tashkent, thereby expanding his empire to the west and south.

The Seljuk army suffered a great death toll, and Sanjar barely escaped with his life, but his wife and some of his best warriors were captured.

The Kara-Khitans became the dominant force in Central Asia, and Khwarazm and Karakhanids became vassal states of his empire.

Their empire controlled an area roughly equivalent to most of today's Xinjiang, Kyrgyzstan, Uzbekistan, Tajikistan, and southern Kazakhstan.

At time of his death, the Qara Khitai ruled Transoxiana, Ferghana, Semirechye, the Tarim Basin, and Uyghuria.

The dynasty Yelü established would last until its usurpation by Kuchlug followed by conquest of its domain by Genghis Khan in 1218.