Factual error: When Wulfgar, the little boy, speaks you can tell he is using modern southern Norwegian language. At that time that language didn't exist. Also the old man's translation is far off. (00:09:25)
Continuity mistake: When the guy throws the second shovel of dirt on the red haired man, only his lower part of the back gets dirty. Two shots later the dirt is all up his back. (00:45:00)
Continuity mistake: When Hamad and Herger are watching the burning village, Herger has a sip of his horn with its tip pointing up. When it cuts the horn's tip is pointing down. (01:00:20)
Visible crew/equipment: In a scene in a cave that is the lair of the "eaters of the dead," the camera takes an overhead wide angle shot of the "eaters" walking down into the cave. It is possible to see a young man wearing a burgundy t-shirt and beige shorts (a crew member), sitting against the wall of the cave cross-legged. (01:16:55)
Suggested correction: I've watched this scene a number of times on YouTube and I'm certain that this "crew member" is an extra. He is not wearing a T-shirt and shorts, his clothing is correct for an extra. There are also other extras sat cross-legged a few feet from him.
Visible crew/equipment: Before the last battle, when the Wendol warlord nears the Norse village he's on horseback and raises his arm swinging his weapon. It cuts to his closeup, and under his right arm there's a visible plastic slider buckle on the strap (looks like nylon) of his bear costume. (01:21:15 - 01:30:55)
Revealing mistake: During the final battle, Buliwyf's dog mauls a Wendol warrior. As he does so you can see the obviously rubber bear's tooth on his headress bend as the dog's head catches it.
Revealing mistake: When the fireworm has descended upon the town and after Ahmed finds out the Wendol are human, you can see that he stabs the Wendol right through his side, not his chest.
Factual error: The clothing and most noticeably the armour of the Viking warriors is a very higgledy piggledy collection of dress from different places and times in history. Only Buliwyf actually seems to be wearing armour of Viking origin, some of the others have Spanish Conquistador armour and helms from centuries after the film is set and another wears a Roman gladiator's helm complete with face mask, another of the group is seen to be wearing a kilt (the redhead conveniently played by one of the two Scottish actors used as Vikings)which may well have been worn concurrently by their celtic neighbours but his kilt is quite modern in design.
Continuity mistake: When the Wendol are attacking the village at night, one of them is shot by an arrow and falls off his horse into water. A couple of minutes later the same shot of the Wendol falling is used again for another arrow hit.
Continuity mistake: Before the first battle scene, the king is telling them about the Wendol. The black-haired man is riding his horse back to the castle. He walks up and is taking off his gloves. There is a shot to the king and back to the black-haired man, and his gloves are back on his hands.
Factual error: The Vikings follow the Norse religion, and make several references to it throughout the movie. But when waiting for the first Wendol attack, Herger states "The All-Father wove the skein of your life a long time ago". In Norse mythology, the All-Father (Odin) did not weave the skein of life, the Norns did.
Suggested correction: The movie takes place in the 900s AD, and Norse myth wasn't put in writing until centuries later with the Prose Edda in 1220. Prior to that, it was spread through oral tradition; who's to say the details didn't change/update in the retelling over the next couple of centuries?
