Dictionary of Medieval Names
from European Sources

Grimberg f. Old High German, Old Saxon grim 'grim, fierce, bold' + Old Norse, Old High German berg 'mountain, hill' or Old High German burg 'castle, city, stronghold'.

France
Latin
c823 Grimberga (nom) irminon-vol2 13, CE
Cite as: S.L. Uckelman. "Grimberg". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2020, no. 1. http://dmnes.org/2020/1/name/Grimberg.