Alan, In my branch of the Agar family from Sheffield, England, the name is derived from its Hebrew version which is Eger. My paternal grandfather changed it to "Agar" because that is how the English pronounced it. This is not much help to you, but thought you might find it interesting. As for the Viking version re: Agar, could be true, as for a time, they ruled England. Funny thing is, on my mother's Scottish side, (Nicol) I found that we are descended from the Vikings! Good luck, Ruth