Vikings follows the adventures of Ragnar Lothbrok: the greatest hero of his age. The series tells the saga of Ragnar’s band of Viking brothers and his family as he rises to become King of the Viking tribes. As well as being a fearless warrior, Ragnar embodies the Norse traditions of devotion to the gods: legend has it that he was a direct descendant of Odin, the god of war and warriors.
The detail that the Norse men where tattooed are not fantastical speculation. Eyewitness account from the viking age report that the vikings where indeed tattooed. This was also a feature of Celts and Slavs alluding to that the practice was widespread in pagan Europe.
The Viking Age government is shown to be theocratic. In reality, the government of the Viking Era was more geared towards being essentially democratic. The Norse had the legal and religious right to dispose of their kings which where elected in votes.