Tongguan (756) — the same event in Old Book of Tang and New Book of Tang

Old Book of Tang: Geshu Han was captured by his subordinate Huoba Guiren and surrendered to the enemy, and Tongguan could not be held.; New Book of…

What each source says

Old Book of Tang (Jiu Tangshu), Annals · AD 756 · 潼關

Geshu Han was captured by his subordinate Huoba Guiren and surrendered to the enemy, and Tongguan could not be held.

辛卯,哥舒翰至潼關,為其帳下火拔歸仁以左右數十騎執之降賊,關門不守,京師大駭,河東、華陰、上洛等郡皆委城而走。
Location: 舊唐書 卷9 天寶15年 6月

New Book of Tang (Xin Tangshu), Annals · AD 756 · 潼關

Huoba Guiren captured Geshu Han and surrendered to An Lushan; Tongguan fell.

蕃將火拔歸仁執哥舒翰叛降于安祿山,遂陷潼關、上洛郡
Location: 新唐書 卷005 睿宗·玄宗 天寶15年6月

Place: 潼關

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