Quote Originally Posted by Viking View Post
There was Old West Norse and Old East Norse. The point was though how much modernity has had an influence on the lingual unity. In Norway at least, I am pretty certain that the different Norwegian dialects at the time (if any) must have been more intelligible than what they are today. Modern western Norwegian and eastern Norwegian are about as different from each other as standard Swedish is from either.
Mutual intelligability exists on multiple levels, the level at various periods between Scandanavia and England is instructive, as is the level within England. In both cases, I believe it depended on how far and often you traveled, but unity only comes with a written standard. When that was achieved in Norway I'm not sure, but it can't be before Cnut started using English missionaries to convert the populace.