《旧唐书·本纪·卷十二》
皇上与太子、诸王、妃子、公主一百多人出皇宫花园北门，右龙武军使令狐建正在军中教士兵射箭，听说皇上遇难，马上聚集弓箭手四百人护驾跟从。
与太子诸王妃主百余人出苑北门，右龙武军使令狐建方教射于军中，闻难，聚射士得四百人扈从。
The emperor, the crown prince, the other princes, the concubines, and the princesses (over 100 people in total) left the palace through the North Gate of the imperial gardens. Linghu Jian, the Commander of the Right Dragon Warrior Army, was teaching his soldiers archery on the parade ground. When he heard that the emperor was in danger, he immediately rallied 400 archers to escort him.