Dictionary of Medieval Names
from European Sources

Frederius m. Old High German fridu, Old Saxon frithu 'peace' + Old English here, Old High German heri 'host, army'.

France
Latin
1135 Frederii (gen) clairvaux-12thc 7, Frederius (nom) ibid. 7; 1147 Frederii (gen) ibid. 14, Frederio (abl) ibid. 14, Frederius (nom) ibid. 14
Cite as: S.L. Uckelman. "Frederius". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2017, no. 1. http://dmnes.org/2017/1/name/Frederius.