Ivar is crowned the new king of Kattegat just in time to welcome Rollo home. Bjorn, Lagertha and Ubbe must rely on unsteady alliances to survive.

Bjorn’s fleet sails onward and launches a surprise attack. Back in Kattegat, Lagertha continues in her quest for power.

Ragnar and Ivar plot against the Saxons and reach a new level of understanding.

Floki learns of the heavy price he has paid for his actions. Rollo finds an unlikely ally in Count Odo. Bjorn has to fight a fierce opponent in the wilderness.

As Ragnar and Floki remain at odds, Rollo makes great efforts in Paris to win over his new bride, Princess Gisla. Meanwhile, King Ecbert sets the task for his son…

A dangerously ill Ragnar returns to Kattegat, where his suspected death kicks off a scramble to succeed him. Meanwhile, Lagertha engages in a power struggle with her calculating, former second…

The time has come for an unlikely alliance to band together for a new raid on England; a storm pushes the Viking fleet to a new destination; Ragnar and his…

The battle begins between Ragnar and King Horik’s forces against Jarl Borg; Princess Aslaug makes her way to Kattegat.

Ragnar, weak and still hurt, must meet the Earl head-on after it comes to light that Rollo has been tortured on Haraldson’s orders. The two men will come together face…

Ragnar and his crew sail out with Earl Haraldson’s permission.

A seer reads Earl Haraldson’s future and tells him that Ragnar searches for his death.