It is a great series. Some liberties are taken for sure. I don’t know if the early Vikings knew of the British Isles or not. It is clear they did in fact raid into Russia first. I don’t think whether that or not the Earl knew is really relavant, though it the conflict should make of a better story.
"Some" liberties? Read the article. They got the Viking political structure completely wrong.
Its enjoyable enough to watch. I watch the Walking dead and they’ve taken one or two liberties with reality too.