History of Liao
It is not known when Yaonian Yanmujin was born. (She is referred to in traditional historical sources (such as the "History of Liao") as Xiao Yanmujin because, according to the "History of Liao", Emperor Taizu greatly admired Emperor Gao of Han, and so referred to his own Yelü clan by the name of Liu as well, while he had the names of the traditional wife clans of Yelü chieftains — the most prominent of whom included the Yishi (乙室) and Bali (拔裏) clans — change their names to Xiao (after Emperor Gao's prime minister Xiao He), and thus almost all Liao empresses, both actual and posthumously honored ones, were known by the surname of Xiao.) Yaonian Yanmujin was of the Yaonian clan, and was a daughter of the chancellor Yaonian Tila (遙輦剔剌).