Emperor Gaozong died at the age of 56 in Luoyang at Zhengguan Hall, leaving an edict that the crown prince should ascend. (Old Book of Tang (Jiu Tangshu), Annals 舊唐書 卷5 弘道1年 12月)
Emperor Gaozong died in the Zhenguan Hall at the age of 56; the era was changed to Hongdao. (New Book of Tang (Xin Tangshu), Annals 新唐書 卷003 高宗 弘道1年12月)
In March 683 (Gengyin day), Ashina Gudulu and Ashide Yuanzhen besiege the Chanyu Protectorate, and capture and kill its Sima Zhang Xingshi. (Zizhi Tongjian (Comprehensive Mirror) 권203 683년 항)
In May 683 (Yisi day), Gudulu and others invade Yuzhou and kill its governor Li Sijian; Cui Zhibian, Governor-General of Fengzhou, blocks them north of Zhaona Mountain, is defeated and captured. (Zizhi Tongjian (Comprehensive Mirror) 권203 683년 항)
In December 683, that night the emperor summons Pei Yan and by testamentary edict entrusts him with assisting the government; the emperor dies in the Zhengguan Hall. (Zizhi Tongjian (Comprehensive Mirror) 권203 683년 항)