|“||My only ambition is revenge!||”|
Prior to the events of the series, Kjetill's father, Eric Trygvasson, killed Rafarta's brother Sigvard Strut in a land dispute. Presumably a potential feud was averted by the marriage of Kjetill's daughter Thorunn and Rafarta's son Helgi "the Lean" Eyvindsson.
Floki returns to Kattegat after discovering Iceland and proceeds to recruit people to settle there with him. The promise of "living in the land of the gods" attacks Kjetill and his family, despite Queen Lagertha forbidding Floki from taking warriors from Kattegat. Kjetill and his daughter Aud are chosen as chiefs of the expedition, along with Eyvind and Guthrum.
The expedition is betrayed by Guthrum, who informs Lagertha about Floki's plans. Lagertha decides to allow the expedition to continue though. On the journey to Iceland, Aud muses that they were spared because of women's inherent patience. Her thinking puzzles Kjetill.
Upon arriving in the "promised lands," the group is distressed by the grim appearance of the Icelandic coast. Kjetill tries to console everyone by saying it can't be as bad as it looks. The settlers begin creating their settlement near some hot springs in their new land. Floki proposes a cooperative, democratic approach to governing their new society. However, Eyvind doesn't trust Floki and accuses him of wanting to be king. Later, Kjetill privately informs Floki of his suspicions that Eyvind himself wants to be king of the new land. Floki suspects that Eyvind wants to provoke a reaction from them and implores Kjetill not to act against Eyvind.
Kjetill has Floki's temple of Thor raised on his land. During the construction and blessing of the temple, an argument is provoked between one of Eyvind's sons, Bul "the Dog" Eyvindsson and Kjetill's son Thorgrim. Thorgrim ends up stabbing Bul, and is later found drowned. Floki takes the blame for the frictions in the colony and offers himself up as a sacrifice of atonement. But Kjetill and his family votes against Floki being sacrificed, winning when Kjetill's son-in-law Helgi joins their side against his family's.
Later, Kjetill's daughter and Helgi's wife Thorunn vanishes. Through a vision, Floki finds out that Eyvind's son Asbjorn murdered her and hid her body. After the body is found, Floki has Eyvind and his family exiled from the settlement.
Some time later, seemingly in the middle of winter, a frostbitten Helgi returns to the settlement to inform Floki and Kjetill that his family is disease ridden and in desperate need of help. Kjetill appears to forgive Eyvind's family and offers to lead a rescue party. He brings his son Frodi, Floki, and several others with him. Helgi leads the group to a hut that has been constructed by Eyvind. Inside is his family looking close to death. Eyvind is genuinely thankful at Kjetill's appearance. However, Kjetill's true intentions become apparent when one of the settlers grabs Floki and holds him at knifepoint. Kjetill proceeds to murder Rafarta and Asbjorn in cold blood, and Frodi kills Jorunn. Floki begs for Helgi's life while Kjetill and his men apparently cannibalize the dead. Kjetill says he will consider sparing Helgi, but come morning a clearly insane Kjetill decapitates Eyvind and Helgi. Their heads are place on spikes, along with Asbjorn's. They group returns to the settlement.
When Floki recounts the massacre to Aud and Ingvild, Aud is driven to suicide by the behavior of her father and brother. Kjetill is indifferent and heartless about his daughter's death. He taunts Floki and states that he feels Aud was more Floki's child than his and does not even both to dig her grave, leaving Floki to do it so that Ingvild will have somewhere to grieve for her daughter. Floki tells Kjetill about the terrible vengeance that the old Floki would have put Kjetill through, but that unlike Kjetill, he has changed.
Kjetill's fate is unknown. He is last seen standing atop a beached whale, laugh-screaming that he is the king of Greenland while surrounded by corpses and the sound of his wife Ingvild crying over the body of their last son. Given that Kjetill is known to have made it from Iceland to Norway on his own before, which is a much longer journey that Greenland to Iceland, and that he has access to a massive source of food, in theory he could make it home.
Kjetill is one of the most frightening characters on the series. He is the strongest and biggest of the Icelandic settlers, at six feet five inches tall. At first, Kjetill seems like a typical Viking patriarch who is intent on following Floki's ideals. When things look grim, he refuses to give up hope, going so far as to say he cannot live without hope.
However, Kjetill's true colors are revealed when Eyvind and his family are too sick and hungry to fight back. He massacres them without hesitation. He continues to reveal that there are no limits to him. He further shows how terrible and evil he is when he decapitates Helgi, who is just as devastated by Thorunn's murder as Kjetill is. Thorunn's murder was arguably worse for Helgi since the killer was his own brother. Kjetill is heartless in his utter indifference to Aud's death. He acts as if he is in charge, not Floki. It is quite possible that Kjetill was not exactly sane all along.
Kjetill is based on the historical figure Ketill Björnsson, nicknamed Flatnose. He was a Norse King of the Isles of the 9th century. His wife was Yngviild Ketilsdóttir, and they had a large family, including Bjǫrn Ketilsson, Helgi "Bjolan" Ketiilsson, Thorunn Ketilsdatter, Jorunn Ketilsdatter, and Aud the Deep-Minded. Most of Ketill's family eventually emigrated to Iceland. He is depicted in the works of Ari Þorgilsson, the Laxdæla saga, Eyrbyggja saga, the Saga of Erik the Red, and his genealogy was described in detail in the Landnámabók.
- Kjetill is loosely based on Ketill Flatnose, an early settler of Iceland and according to some sources a King of the Isles (the Orkney Islands).
- The "Kj" in his name is read as the "ch" in the German "ich." Kjetill represents the Norweigan form of the name. The Icelandic and Old Norse form would be Ketill, with a hard "k."
- The actor of Kjetill is Adam Copeland, who is also a former WWE Superstar, known as "Edge."
|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||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|