Vikings: Every Character Based On Real Historical Figures

Judith of Flanders was the second wife of King Aethelwulf of Wessex. He married her on his way back to England from a pilgrimage to Rome as she was the daughter of King Charles the Bald, the king of West Frankia. She was only twelve years old at the time. She later married Aethelbald, Aethelwulf's son from a previous marriage, and then Baldwin I, the Margrave of Flanders.

In the show she had two sons, one with Aethelwulf and one with Aethelstan. In real life, she only had children with Baldwin I and her on-screen son Alfred the Great was the child of Aethelwulf and his first wife.