Mohammed abu Bakr ibn Ali al Sanhaji al-Baydhaq (died after 1164) was a companion of Ibn Tumart and chronicler of the Almohads. Al-Baydhaq (meaning pawn) was his nickname, because he was small in stature. He was from the tribe of Senhaja.
The title of his main work is: Al moqtabass min kitabi al anssab fi maärifati al ashab (written ca. 1150). It is the most important source on the period. Written in Classical Arabic, Berber words, names and sayings are used throughout the text, making it an important work for scholars of the medieval Berber language.
References
Mohammed al-Baydhaq Wikipedia(Text) CC BY-SA