The chronicler Widukind of Corvey in his Res gestae saxonicae sive annalium libri tres denoted it as the central region of the medieval Duchy of Saxony lying along the middle reaches of the Weser river between Westphalia and Eastphalia.
In his work titled "Res gestae saxonicae sive annalium libri tres," Widukind of Corvey designated this region as the central part of the medieval Duchy of Saxony, which was located along the middle sections of the Weser river between Westphalia and Eastphalia.