Season 1: Lagertha
In season 1, Lagertha was one of the most bad-ass characters in the show despite being a married to a man who always gets his way. When her husband Ragnar bought their son Bjorn to Kattegat to swear his alliance to Earl Haraldson and to earn his arm ring, two men attempt to rape her and her now deceased daughter Gyda, but she fights them off with an sword proving that she’s far more than just a wife.
A similar situation happens when Ragnar finally lets her go on a voyage to England with his men when Earl Haraldson’s half-brother Knut attempts to rape a Saxon woman. Lagertha saves her and kills Knut causing Ragnar to take the blame for his death almost leading him to the chopping block, if not for his brother Rollo who testified on his behalf.
After Ragnar defeated Haraldson and becomes Earl, Lagertha struggled with fertility resulting in a miscarriage of their third child causing Ragnar to question whether or not Lagertha could provide him with the sons he desires.