Lydia

Askeladd's mother. Lydia (リディア Ridia) was a Welsh noblewoman who was captured and enslaved by the Norse warrior Olaf.Lydia was a lean woman with long light blonde colored hair and blue eyes. She dressed in a simple gray robe.Not much is known about Lydia’s personality, however, she cared deeply for her son Askeladd.

(Source: Vinland Saga wiki edited)