Season synopsis
Contains spoilers for this season and earlier seasons.
Ragnar returns wounded from Paris, while Rollo marries Gisla and joins the Franks. Bjorn has Floki arrested for Athelstan’s killing, and Ragnar later confines him in a cave before releasing him. Helga mourns their daughter’s death. Lagertha kills Kalf before their wedding and reclaims her earldom. The next Paris expedition ends in defeat against Rollo’s defenses, sending Ragnar home in disgrace. Years pass before he returns to Kattegat, where his grown sons have begun planning lives beyond him.
Only Ivar accompanies Ragnar’s final journey to England. Their ships are wrecked, and they eventually surrender to Ecbert, who guarantees Ivar’s return home but hands Ragnar to Aelle. Before they part, Ragnar tells Ivar to avenge him against Ecbert. Aelle tortures Ragnar and kills him in a snake pit. Meanwhile, Lagertha seizes Kattegat and shoots Aslaug after promising her safe passage. Ragnar’s sons unite a great army to avenge their father, capture Aelle and execute him by the blood eagle.
The army then defeats Aethelwulf in Wessex. Ecbert abdicates to his son and stays behind to negotiate with the invaders. He offers East Anglia in exchange for choosing his own death, concealing that his abdication makes the grant worthless; he dies in his bath. Helga is killed by Tanaruz, leaving Floki bereaved and ready to depart. The brothers disagree over whether to keep raiding England or sail farther afield. When Sigurd insults Ivar, Ivar throws an axe into his brother’s chest and kills him.