No. of episode	Title	Original air date
1	"Brother's War"	February 27, 2014
Rollo battles Ragnar when Jarl Borg and King Horik's men clash. Rollo surrenders to Ragnar after admitting he cannot kill him. Ragnar negotiates an unsteady truce between Borg and Horik, then returns to Kattegat. Ragnar's attempts to reconnect with his wife are hampered when Lagertha learns about his affair with Aslaug. Ragnar finally mourns for his dead daughter, Gyda. Ragnar's life becomes more complicated when a ship arrives bearing a visibly pregnant Aslaug. Rollo is placed on trial, but is shocked when freed by the lawkeeper, who has been bribed by Ragnar. Despite Lagertha's enmity towards Aslaug, Ragnar decides to take the princess as his second wife. Humiliated, Lagertha leaves Ragnar and Kattegat. Ragnar tries to stop her and pleads with her to return, but she rebuffs him. Ragnar's sorrow is multiplied when Bjorn rejects him and goes away with his mother.
No. of episode	Title	Original air date
2	"Invasion"	March 6, 2014
Four years later, Ragnar finally announces plans to raid England. Horik and Borg arrive, but his resentment leads Ragnar to break the pact with Borg. Ragnar accepts Rollo back into his family, but forbids him from raiding. The Seer tells Ragnar that his sons will be more famous than him. Ragnar and Horik's men set sail for England, but a violent storm throws them off course. While exploring, they are ambushed by soldiers and several men are killed including one of Horik's sons. Athelstan saves Ragnar's life during the fight. They learn that they are in Wessex, which is ruled by King Ecbert, a man described as similar to Ragnar.
No. of episode	Title	Original air date
3	"Treachery"	March 13, 2014
Ragnar and his men move deeper into Wessex. He believes the land's greatest wealth is its rich soil, which could support a Viking colony. Ecbert sends envoys to ask Ragnar to leave; Ragnar replies asking what Ecbert would be willing to pay. In Hedeby, Lagertha is now remarried to an abusive husband, earl Sigvard, and both she and Bjorn are unhappy. Bjorn wants to go out into the world and prove his manhood, but his stepfather won't allow it. Meanwhile, Jarl Borg remarries and decides to seize Ragnar's lands in retaliation for Ragnar breaking their truce. With all the able warriors gone, Rollo rallies the village's women, children and elderly, but Borg massacres them and seizes control of Kattegat. Rollo is forced to flee with Ragnar and Aslaug's sons.
No. of episode	Title	Original air date
4	"Eye for an Eye"	March 20, 2014
Ragnar meets King Ecbert, who questions his reasons for staying in Wessex and offers to grant him some land. Later, back at camp, one of Horik's ships arrives with news of Jarl Borg's sacking of Kattegat. Ragnar and his men set sail for home. Athelstan chooses to remain with Horik, but is later captured by soldiers after his hunting party is ambushed. Rollo hides Aslaug, Siggy and the other survivors at a remote homestead and tries to rally others to help them retake Kattegat. Ragnar returns home and finds his family. His happiness is soured by Rollo's revelation that they do not have enough men to defeat Borg. In Wessex, Athelstan is branded an apostate and crucified, but his life is saved when Ecbert arrives and orders him taken down from the cross. Ragnar is surprised when a large group of fighters arrives led by Lagertha and Bjorn. Ragnar is overjoyed to be reunited with his son.
No. of episode	Title	Original air date
5	"Answers in Blood"	March 27, 2014
Concerned that Borg is heavily entrenched, Ragnar plans to lure him away from Kattegat. Ragnar and Bjorn sneak into the town at night and set fire to the winter food stores, forcing Borg to give chase. Ragnar engages Borg's forces in a bloody battle, and Borg's host is routed and forced to flee. Ragnar reenters Kattegat, and Bjorn is asked to sacrifice a prisoner to the gods. Ragnar visits the Seer and confesses that he wants both Lagertha and Aslaug as his wives. In Wessex, Athelstan is kept at Ecbert's court, giving the king insight into pagan beliefs. Athelstan struggles with his former Christian beliefs. Lagertha gives Bjorn permission to remain in Kattegat with Ragnar, but chooses to return to her husband. A messenger arrives and informs Ragnar that Ecbert's forces have slaughtered Horik's men, with Horik and his son, Erlendur, barely escaping.
No. of episode	Title	Original air date
6	"Unforgiven"	April 3, 2014
King Horik returns to Kattegat, defeated by King Ecbert and with few of his forces surviving. Hungry for revenge, Horik tells Ragnar that they need the help of Jarl Borg again, since he has many ships. Aslaug is not pleased and asks Ragnar not to listen to Horik. Rollo is sent as emissary to Götaland to negotiate with Jarl Borg, the latter accepts the offer after consulting with the skull of his first wife. Athelstan becomes a confidant of King Ecbert, entrusted to look after secret Roman scrolls and relics. Lagertha returns home to a displeased Sigvard who sends men to beat her during the night. He tries to humiliate her further the next day, but she plunges a knife into his eye and his nephew Einar beheads him. Jarl Borg returns to Kattegat to join forces with Ragnar, but during the night his men are burned alive and he is taken captive.
No. of episode	Title	Original air date
7	"Blood Eagle"	April 10, 2014
Horik and Ragnar agree that they need more ships and warriors to return to England. Horik persuades Ragnar to delay killing Jarl Borg, in case his execution scares off potential allies. Helga reveals that she is carrying Floki's child and they agree to wed. When Helga seeks Ragnar's blessing, Floki claims they do not need it. Ragnar visits the Seer who reveals that Athelstan is alive but spiritually torn. In England, King Ecbert proposes an alliance with King Ælla against the expected return of the Vikings. To win over a suspicious Ælla, Ecbert marries his son to Ælla's daughter to seal their alliance. Ragnar's call for an ally is answered by a mysterious Earl, who is revealed to be Lagertha. Aslaug tells Ragnar she is pleased that Lagertha is joining forces with him. Bjorn continues to be rebuffed by Þorunn, the slave girl. Rollo forces Siggy to admit she is sleeping with Horik. Horik tricks Borg into thinking he will escape his fate, but in the end Borg is led into town to be executed. Ragnar performs the Blood Eagle ceremony on Borg.
No. of episode	Title	Original air date
8	"Boneless"	April 17, 2014
Aslaug's prophesy comes to pass when she gives birth to a son with malformed legs. Despite Ragnar's insistence that he should have no future in Viking society and must die, Aslaug keeps him. Ragnar names him Ivar the Boneless. Lagertha arrives in Kattegat with her ships and warriors. In Wessex, Ecbert receives Princess Kwenthrith of Mercia, who is in civil war with her family after murdering her brother. Kwenthrith takes a sexual interest in the Northmen and Athelstan. Sensing Floki's growing rift with Ragnar, Horik attempts to entice him to his side. After landing in Wessex, Ragnar decides on his own to send Torstein to inform Ecbert of their arrival, annoying Horik and Lagertha. Aethelwulf and a group of soldiers arrive, and he invites Ragnar to speak with his father. As a sign of goodwill, Aethelwulf returns Athelstan's bracelet to confirm that the monk is still alive. Despite Ragnar's promise of safety, Aethelwulf's group is ambushed by Northmen led by Erlendur. The entire group is slaughtered except for Aethelwulf who is allowed to escape.
No. of episode	Title	Original air date
9	"The Choice"	April 24, 2014
While reviewing old Roman texts with Athelstan, Ecbert sees a way to defeat the Vikings. Horik advances towards what he thinks is the Wessex army, but Ecbert catches the Vikings between two troops of cavalry and defeats them. Rollo is badly injured, but is recognised by Athelstan and taken back to Winchester. Ragnar names his son Björn Ironside, as he is unscathed. Ælla wants to destroy the remaining Vikings but instead Ecbert decides to offer them land and to employ them as mercenaries to fight against Mercia. Rollo is returned to the Vikings, and some of them volunteer to fight for Kwenthrith. Athelstan returns to Kattegat with the Vikings, admitting to Ragnar that he holds belief in both the Christian and Norse gods now. Meanwhile, Þorunn has been made a free woman.
No. of episode	Title	Original air date
10	"Rites of Passage"	May 1, 2014
Horik's wife and children arrive in Kattegat and the village celebrates. To prove to Horik he is trustworthy, Floki poisons Torstein. Horik reveals his plan to kill Ragnar and his entire family. In return for a promise to marry her, Horik orders Siggy to kill Ragnar's children. Bjorn and Þorunn finally reconcile and commit to each other. Athelstan teaches Ragnar the Lord's Prayer. With reinforcements, Horik attacks Kattegat. Arriving in the main hall, he discovers Torstein alive, and sees that Floki and Siggy did not betray Ragnar. Ragnar and his closest circle kills Horik and claims his "King's Sword", while Ragnar's men slaughter all of Horik's children, save Erlendur. Ragnar is now king, sitting atop the iconic cliff Preikestolen.