Season 3: Aslaug
In season 3, Asluag and Ragnar’s relationship takes an ugly turn. She is unhappy in their marriage and believes that Ragnar does not love her anymore. In fact, she becomes downright villainous this season when it comes to the welfare of her children.
With Ragnar gone in England, a mysterious man named Harbard arrives in Kattegat, who is able to calm Ivar and stop his suffering. Him and Aslaug end up having an affair resulting in her leaving her four young boys in the hands of Siggy, which turns out to be disastrous when two of the boys fall though a frozen lake and Siggy dies in the process of saving them.