Dag, King of Westmare (the district around Langesund fjord) appears to have been created to give importance to Hlif, his daughter, the wife of Halfdan the Mild.
Ynglingsaga
There is only one reference to Dag of Westmare in the Ynglinga Saga, making him the father of Hlif of Westmare who married Halfdan Eysteinsson the Mild. No parents or wives are mentioned for Dag.[1] This is all it says: "Hann átti Hlíf, dóttur Dags konungs af Vestmörum."
Medieval Lands
He is mentioned in Medieval Lands as the father of Hlif of Westmare who married Halfdan Eysteinsson the Mild. No wife is mentioned [2]
Sources
↑ Snorri Sturluson: Sagas of the Norse Kings. The Ynglinga Saga. Translated by Samuel Laing, revised by Peter Foote MA. Everyman's Library Dutton New York SBN 460 00847 1 Page 41
↑ Medieval Lands: Denmark: Halfdan Mildi
This person was created through the import of Rodney Timbrook Ancestors and Relatives_2010-09-10.ged on 10 September 2010.
This person was created on 21 March 2011 through the import of LJ Pellman Consolidated Family_2011-03-21.ged.
Gordon Lokken, firsthand knowledge.
Abt 0740 - 