Season 2: Lagertha
In season 2, Lagertha tries to be okay with Ragnar’s affair, but once a very pregnant Aslaug arrives in Kattegat, it’s game over. She makes the bold decision to leave Ragnar taking their son with her and years later ends up in Hedeby in an abusive relationship with Earl Sigvard who wants her to be more of a housewife than a shieldmaiden.
When she learns that Ragnar has been usurped by Jarl Borg, Lagertha attempts to convince Sigvard to send an army to help Ragnar reclaim his land. When he refuses, Lagertha and Bjorn bring a small army to aid Ragnar, and when she arrives home, Sigvard has her brutally beaten and later attempts to disrobe her in front of their dinner guests.
It’s the final straw though and Lagthera stabs him in the eye with a knife. Another man ends up chopping off his head, and Lagertha is named Earl of Hedeby.