When Gunnhild is first introduced, she is with her husband, Jarl Olavsonn and also with King Harald on a ship. While he was discussing his ambitions with her and her husband, he also talks about his desire to kill Lagertha for kiiling his wife Astrid. She then comforts him and confidently tells him that he will be happily married one day and this causes Harald to be immediatley smitten with her. In the battle against King Alfred’s Army, Gunnhild stabbed and killed Bishop Heahmund through the back, while he was wounded. She later faced Bjorn Ironside during the fight, slicing him on the forehead in the process before being knocked to the floor, forced to surrender to him as the Viking army retreated. She is captured by the Saxons after the Battle of Marton, where she eventually meets Bjorn. Her and Bjorn both shared a connection and quickly fell in love, despite King Harald having an interest in her. She falls in love with Bjorn, soon after. Later she becomes Bjorn's wife and the ultimate love of his life.
When Bjorn once again struggles with being faithful to his wife, Gunnhild solves the problem by suggesting her take Ingrid as a second wife. Bjorn goes along with her plan. It's an interesting solution to a problem Bjorn has always had with his women. Once he's "made his conquest" he tires quickly and moved on to another woman.
Gunnhild claims she is not jealous of Ingrid, but during the celebration feast, she taunts Ingrid, clearly not nearly as comfortable with this new arrangement as she pretends. When Erik the Red comments on her apparent lack of jealousy, she rebukes him by telling him that he does not know her or her feelings.
Gunnhild puts on a brave face, telling Bjorn to go to Ingrid on their wedding night. He lingers, obviously guilty over the pain he's caused her. But she insists. He made a decision and now he needs to follow through with it. Gunnhild acts tough, but when Bjorn leaves, a tear slides down her cheek.
When King Hakon arrives in Kattegat to offer his support in the fight against the Rus, Gunnhild is sitting on Bjorn's throne. She takes him to speak with Bjorn who is bedridden and dying. Upon Bjorn's death, Gunnhild tells the story of Bjorn to keep her husband's name and exploits alive in the people's hearts. Her eulogy for Bjorn is a heartfelt and slyly political speech. She states that Bjorn is "the King of all Norway" even though King Harald technically was the one ordained as such. This is a sly move on her part as this would make her the "Queen of all Norway."
Upon Bjorn's death, Kattegat needs a new ruler. Erik the Red convinces Gunnhild that she should stand to be elected. Unbeknownst to her, he is also convincing Ingrid that she should become queen. When Ingrid reveals to Gunnhild that she is pregnant, Gunnhild tells her that the baby is Harald's. Ingrid disagrees, saying she was pregnant before she was raped by him, and thus the baby is Bjorn's. Erik continues playing both women. He even manages to convince Gunnhild to sleep with him, despite her grief over Bjorn's death.
When Harald returns to reclaim Bjorn’s throne, he decides to take Gunnhild as his queen. Upon learning that Ingrid is pregnant, he believes that the child is his because he raped Ingrid. He announces he will marry Ingrid as well and have the same two wives that Bjorn once had. At the wedding, Gunnhild tells them she won’t be joining them in matrimony as in her heart she is still married to Bjorn. She then jumps into the water and drowns herself to be reunited with her beloved in Valhalla.
Gunnhild is a strong, fierce, unique, and loyal shield-maiden. She is strong enough to hurt Bjorn on the battlefield. She is also a kind, affectionate, and humble. She tried to make Harald feel better about his bad luck in love, consoled Bjorn when he was depressed by the disappearance of his mother, and made Bjorn show his feelings for her. Even though she feels a great love and respect for Bjorn, she does not hesitate to challenge him, even hitting him two times. Gunnhild naturally takes on the leadership role as Queen of Kattegat. It is a testament to Gunnhild that she is willing to provide a guiding hand to Ingrid, despite her being "the other woman." Gunnhild has always been aware of all of Bjorn's faults and his strengths, and she loves him for it all.
Gunnhild is loosely based on the historical Gunnhild Gormsdóttir, also known as Gunnhild, Mother of Kings. While the life of the real Gunnhild is vastly different from the Gunnhild portrayed in the series, they share the same personality. The historical Gunnhild was the wife of Eric Bloodaxe, King of Norway from 930 to 934 AD. She appears in the Icelandic Sagas. She lived during a time of great change and upheaval in Norway. Her father-in-law was Harald Fairhair. She and her husband Eric Bloodaxe spent much of their life exiled in Orkney, Jorvik, and Denmark. They had many children, a number of whom became co-rulers of Norway in the late tenth century.
|Season five appearances|
|The Departed Part 1||The Departed Part 2||Homeland||The Plan||The Prisoner|
|The Message||Full Moon||The Joke||A Simple Story||Moments of Vision|
|The Revelation||Murder Most Foul||A New God||The Lost Moment||Hell|
|The Buddha||The Most Terrible Thing||Baldur||What Happens in the Cave||Ragnarok|
|Season six appearances|
|New Beginnings||The Prophet||Ghosts, Gods, and Running Dogs||All The Prisoners||The Key|
|Death and the Serpent||The Ice Maiden||Valhalla Can Wait||Resurrection||The Best Laid Plans|
|King of Kings||All Change (Season 6)]]||The Signal||Lost Souls||All At Sea|
|The Final Straw||The Raft of the Medusa||It's Only Magic||The Lord Giveth||The Last Act|