Lagertha

Among them was Ladgerda, a skilled Shieldmaiden, who, though a maiden, had the courage of a man, and fought in front among the bravest with her hair loose over her shoulders. All-marvelled at her matchless deeds, for her locks flying down her back betrayed that she was a woman.

From Wikipedia, the free encyclopedia

Lagertha was, according to legend, a Viking shieldmaiden from what is now Norway, and the one time wife of the famous Ragnar Lodbrok. Her tale, as recorded by the chronicler Saxo in the 12th century, may be a reflection of tales about Þorgerðr Hölgabrúðr, a Norse deity.

Her name as recorded by Saxo, Lathgertha, is likely a Latinisation of the Old Norse Hlaðgerðr (Hladgerd). It is frequently rendered in English-language sources as "Lagertha", and has also been recorded as Ladgertha, Ladgerda or similar.

for more detail see Wikipedia and Saxo