Dictionary of Medieval Names
from European Sources

Dagmar m. Old Saxon, Old Dutch dag, Old High German tag 'day' + Old High German, Old Saxon māri from Proto-Germanic *mērijaz 'famous'.

Germany
Latin
1200 Dagmari (gen) hennes-vol1 5
Cite as: S.L. Uckelman. "Dagmar". In S.L. Uckelman, ed. The Dictionary of Medieval Names from European Sources, Edition 2016, no. 4. http://dmnes.org/2016/4/name/Dagmar.