Luoyang (683) — the same event in Old Book of Tang, New Book of Tang and Zizhi Tongjian

Old Book of Tang: Emperor Gaozong died at the age of 56 in Luoyang at Zhengguan Hall, leaving an edict that the crown prince should ascend.; New Book…

What each source says

Old Book of Tang (Jiu Tangshu), Annals · AD 683 · 洛陽

Emperor Gaozong died at the age of 56 in Luoyang at Zhengguan Hall, leaving an edict that the crown prince should ascend.

」是夕,帝崩於真觀殿,時年五十六。
Location: 舊唐書 卷5 弘道1年 12月

New Book of Tang (Xin Tangshu), Annals · AD 683 · 洛陽

Emperor Gaozong died in the Zhenguan Hall at the age of 56; the era was changed to Hongdao.

皇帝崩于貞觀殿,年五十六
Location: 新唐書 卷003 高宗 弘道1年12月

Zizhi Tongjian (Comprehensive Mirror) · AD 683

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.

是夜,召裴炎入,受遺詔輔政,上崩於貞觀殿。
Location: 권203 683년 항

Place: 洛陽

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