In the 10th episode (mid-season finale), victory proves costly in the battle between the Vikings and the French as Ragnar squares off against Rollo, sealing the fates of the two brothers.
As they near Paris, the Vikings relaunch their boats, but this time they bear interesting structures made by Floki; Aethelwulf and Alfred arrive in Rome, where honors are bestowed by Pope Leo IV, but in Wessex, relations are less than cordial between King Ecbert and a disgruntled King Aelle.moreless
As Ragnar prepares to take his troops for one more daring attack on Paris, he makes a request of his son that could change the future of the Vikings for ever.
Tragic circumstances greet the fleet on its return to Kattegat; Lagertha is usurped and convinces Ragnar to help her reclaim her title.
As the new Viking settlement prepare for their first harvest, King Ecbert pays them a visit.
A mysterious wanderer arrives in Kattegat; Lagertha and Athelstan establish a Viking settlement.
King Ecbert proposes a deal to the Vikings in the Season 3 premiere. Later, Ragnar leads his forces into battle.
When safely back at Kattegat with King Horik, Ragnar only trusts those who stood by him.
Justice is dealt to Jarl Borg, and allies are made on both sides of the sea.
Ragnar receives an unexpected offer from King Horik and Lagertha's new husband doesn't seem overly pleased to see her. Meanwhile, Athelstan becomes King Ecbert's trusted aide.
Lagertha is once again reunited with Ragnar and Bjorn make another choice. Meanwhile, Athelstan finds it difficult to define his faith and Aslaug has to accept the consequences of her prophecies.
While Ragnar meets Ecbert in search of a compromise, Rollo must lead his people. Meanwhile, Jarl Borg imposes a strict rule on Kattegat.
Four years have passed and Ragnar leads a new series of raids on England.
While a plague ravages the village of Kattegat, Ragnar sets off towards Götaland, where he must settle land dispute with Jarl Borg.
Athelstan comes to realise just how strong his Christian faith remains, when he accompanies Ragnar and Lagertha on the traditional Viking pilgrimage to Uppsalla.
When Ragnar discovers that Earl Haraldson ordered Rollo's torture, a confrontation between the two men is inevitable.
Earl Haraldson allows Ragnor to return to England, where an explosion of violence and mayhem are unleashed onto the unsuspecting town of Hexam.
It is 793 AD and Viking warrior Ragnar Lothbrok wants to go to the West in search of riches, rather than following the old tradition of raiding the East. However, getting the permission of Head Man, Earl Haraldson, is not going to be easy.moreless