Mel Gibson wants you to hear real Viking language.
"I want a Viking to scare you. I don't want a Viking to say, "I'm going to die with a sword in my hand."
I don't want to hear that. It pulls the rug out from under you. I want to see somebody who I have never
seen before speaking low guttural German who scares the living sh*t out of me coming up to my house.
What is that like? What would that have been like?" Gibson is unsure whether it'll be in Old Norse or Old
English. "Whatever the 9th century had to offer. I'm going to give you real." Leonardo DiCaprio is going
to have his work cut out for him. But hey, English majors survive this every year, and they pay for the
privilege of pronouncing it.
If the movie is really dealing with the 9th century Viking raids, then the Vikings will speak Old Norse.
If the film decides to deal with them raiding and pillaging England or Ireland, then all their victims can
speak Old English (which was awfully similar even before the Norse lent them all the case endings) and
Gaelic just to make things extra interesting.
Source: Cinematical.com