Ragnar and Lagertha's fleets depart Kattegat once more for Wessex but this time they bring settlers. King Ecbert hosts the Vikings and proposes a deal. Despite the misgivings of some of the other leaders, Ragnar leads his forces into battle once more, but this time as allies of Wessex.

该剧描述了维京人鼎盛时期的故事，他们在当时的北欧地区处于统治地位，因为喜好海上劫掠并不断对外扩张，被人们冠以「北欧海盗」的别号。该剧将侧重于描写维京人的生活、贸易、探索及对外侵袭。