Widukind of Corvey

Widukind of Corvey (c. 920–925 – after 973) was a medieval Saxon chronicler and a monk of monastery of Corvey in Germany during the middle third of the 10th century. His three-volume Res gestae Saxonicae sive annalium libri tres is an important chronicle of 10th-century Germany during the rule of the Ottonian dynasty.

Notable works: Res gestae saxonicae sive annalium libri tres

Source: Wikipedia — https://en.wikipedia.org/wiki/Widukind_of_Corvey