A Swedish friend of mine works as a history teacher, and he sometimes send me little gold nuggets like this.
We don't know if the Scandinavians kept using the English king's face on their coins because they thought that was what coins was supposed to look like, or if they did it because it made it easier to use the coins in England.
It was because the first coins struck by Swedish kings were made by monyers from England (town of Sigtuna, 995). The portraits were pretty generic back then, and not intended to be accurate representations of the kings themselves. It stands to reason that the English monyers used the style they were used to; the important thing with the coins wasn't the look of them, but the silver content. http://www.gorgon.n.nu/penningar-995-1363
@Varangian You are right. After all, scandinavians usuly weighted the silver during trade, rather then counting the coins. This is why coins were cut in pieces in some cases. To not put in more silver then needed.
@FrankHarr
True, but this have been tested and been proven to not be of a significant diffrence. I suspect that most traders of the era knew how to test such things to some degree.
@Varangian Did that mean when they used the scandinavian coins in England they were putting in more than the item sold for or less? Did the Brits cut up coins too?