 In fact, Empress Dowager Shulü's will would soon be challenged.She had intended that Emperor Taizong be succeeded by Yelü Lihu.However, the Khitan chieftains, remembering how she had slaughtered many upon Emperor Taizu's death, decided to support Yelü Bei's son Yelü Ruan the Prince of Yongkang instead, and Yelü Ruan declared himself emperor at Heng Prefecture (as Emperor Shizong).