Season five begins with Ivar the Boneless asserting his leadership over the Great Heathen Army, while Lagertha reigns as Queen of Kattegat. Ivar's murder of his brother Sigurd sets the stage for vicious battles to come as Ragnar's sons plot their next moves after avenging their father's death. Bjorn follows his destiny into the Mediterranean Sea and Floki who is suffering from the loss of his wife Helga, takes to the seas submitting himself to the will of the Gods. This season is full of startling alliances and unbelievable betrayals as the Vikings fight to rule the world.

Vikings returns for a gripping fourth season. Season 3 culminated with the extraordinary battle in Paris, where Ragnar seized victory from the jaws of defeat–but still returns to Kattegat dangerously ill. Thoughts of his death galvanize the forces who seek to succeed him as king, including his wife Queen Aslaug and his oldest son, Bjorn. Meanwhile, Lagertha continues power struggles with her calculating, former second in command, Kalf; Rollo betrays his Vikings heritage by remaining in Frankia and Floki is seized for his brutal actions to the Christian priest Athelstan.

With the promise of new land from the English, Ragnar leads his people to an uncertain fate on the shores of Wessex. King Ecbert has made many promises and it remains to be seen if he will keep them. But ever the restless wanderer, Ragnar is searching for something more... and he finds it in the mythical city of Paris. Rumored to be impenetrable to outside forces, Ragnar and his band of Norsemen must come together to break down its walls and cement the Vikings legend in history.

The series introduces us to the brutal and mysterious world of Ragnar Lothbrok, a Viking warrior and farmer who yearns to explore—and raid—the distant shores across the ocean. His ambition puts him at odds with local chieftain Earl Haraldson, who insists on sending his raiders to the impoverished east rather than the uncharted west. When Ragnar teams up with his boat builder friend Floki to craft a new generation of intrepid ships capable of conquering the rough northern seas, the stage is set for conflict.