The villains in the film, the "tjuder", are not supposed to be vikings, as some sources claim. Tjud or chud is a term historically applied to several Finnic peoples, in the early Russian annals. They often appear in Sami stories (like the one on which this film is based) as traditional, generic villains. Vikings where a trade among the Norse (Scandinavian) Germanic tribes. Note that the clothing and weaponry of the "tjuder" in the film are very different to the ones used by vikings. The script actually stated the "tjuder" to be eastern. But the filmmakers felt it would be offensive to Russian viewers so they made up a language for them to speak, making their origin rather vague.
Remade in 2007, starring Karl Urban and Clancy Brown, this version had the titular character, played by Urban, to be a viking child raised by Native Americans, who then fights the returning vikings some 15 years later.