There was extensive trade between Scandinavia and the Mediterranean, and some of the vikings are believed to have been Muslims from the Middle East and North Africa (“viking” meant armed seafarer, and was a profession and not an ethnicity). Meanwhile, Norse and Icelandic mercenaries worked as the Byzantine empire’s Varangian Guards (they were favoured for their courage, and equally importantly, lack of connection to domestic political intrigues).
There was extensive trade between Scandinavia and the Mediterranean, and some of the vikings are believed to have been Muslims from the Middle East and North Africa (“viking” meant armed seafarer, and was a profession and not an ethnicity). Meanwhile, Norse and Icelandic mercenaries worked as the Byzantine empire’s Varangian Guards (they were favoured for their courage, and equally importantly, lack of connection to domestic political intrigues).
The Varangian guard turned out to be, in general, much… healthier for emperors than the former Praetorian guard.