Harbard (meaning Greybeard in Old Norse) is a wanderer and mysterious storyteller, dreamed of by Helga, Aslaug, and Siggy before he arrives in Kattegat, while most of the men of the town are away raiding.
Harbard's arrival in Kattegat comes after the leading women left in Kattegat all share a repeated dream of a man that seems to be him. In their dream, Harbard is seen holding a ball of snow that is on fire while his hand is bleeding. Helga meets him first when he asks for help with a wound on his hand. He presents himself as a wanderer and a storyteller. He is well-received by Aslaug and Helga, especially after being able to cure baby Ivar's pain. He then has sex with Aslaug, though she is reluctant to do so. Harbard is received with suspicion by Siggy.
Harbard lets Siggy drown when he could have easily saved her. Although it is implied he is letting her reunite with her dead family. After Siggy's death, Aslaug and Helga both become markedly colder towards him. Helga watches Harbard's departure from Kattegat as he vanishes into the fog, further suggesting he is indeed a supernatural being.
Harbard returns to Kattegat while the men are once again raiding, and is first seen at the door of the Great Hall while Aslaug is full of desperation and solitude. He explains to her that he has "heard her calls beyond oceans and has come to answer them." He asks to see Ivar, and when Aslaug asks the boy if he remembers Harbard, Ivar just laughs. Later, when Harbard presents himself as a husband to Aslaug, Ivar starts to become disturbed.
Sigurd discovers that Harbard is sleeping with most of the women in Kattegat. When Aslaug, who already had suspicions about Harbard's behavior, discovers this, she becomes enraged and destroys everything in the Great Hall. Harbard appears to speak with her, despite her anger and jealousy. He peacefully tells her not to try to possess or control him before vanishing once again.
- In "The Lay of Harbardr" (The Hárbarðsljóð), a poem in the Poetic Edda, Thor encounters a ferryman named Harbard, who is really Odin in disguise, and enters a flyting contest, which is a contest of insults, with him. If Harbard is this same person, Floki would be correct in his belief that he is Odin in disguise.
|Season three appearances|
|Mercenary||The Wanderer||Warrior's Fate||Scarred||The Usurper|
|Born Again||Paris||To the Gates!||Breaking Point||The Dead|
|Season four appearances|
|A Good Treason||Kill the Queen||Mercy||Yol||Promised|
|What Might Have Been||The Profit and the Loss||Portage||Death All 'Round||The Last Ship|
|The Outsider||The Vision||Two Journeys||In the Uncertain Hour Before the Morning||All His Angels|
|Crossings||The Great Army||Revenge||On the Eve||The Reckoning|