Battle of 怛羅斯 (751) — the same event in New Book of Tang and Zizhi Tongjian

New Book of Tang: Gao Xianzhi was defeated by the Abbasid Caliphate (Dashi) at Talas.; Zizhi Tongjian: In 751, after five days of standoff, the…

What each source says

New Book of Tang (Xin Tangshu), Annals · AD 751 · 怛羅斯

Gao Xianzhi was defeated by the Abbasid Caliphate (Dashi) at Talas.

高仙芝及大食戰于恆邏斯城,敗績
Location: 新唐書 卷005 睿宗·玄宗 天寶10年7月

Zizhi Tongjian (Comprehensive Mirror) · AD 751

In 751, after five days of standoff, the Karluk tribe turns traitor and joins the Dashi in a pincer attack; Gao Xianzhi is badly defeated, his soldiers nearly annihilated, and only a few thousand survive.

相持五日,葛羅祿部衆叛,與大食夾攻唐軍,仙芝大敗,士卒死亡略盡,所餘才數千人。
Location: 권216 751년 항

Place: 怛羅斯

Show on the map — open New Book of Tang (Xin Tangshu), Annals