Vikings in Iberia
Viking activity in the Iberian peninsula seems to have begun around the mid-ninth century as an extension of Viking raids on and establishment of bases in Frankia in the earlier ninth century. While connections between the Norse and Eastern Islamic lands were well-established, particularly involving the Rus') along the Volga and around the Caspian Sea, relations with the Western edge of Islam were more sporadic and haphazard. Although Vikings may have over-wintered in Iberia, no evidence has been found for trading or settlement. Indeed, the Iberian peninsula may not have offered particularly wealthy targets, in the ninth to tenth centuries. Sporadic raiding continued until the end of the Viking Age.
Medieval warfare
The Vikings were a feared force in Europe because of their savagery and speed of their attacks. Whilst seaborne raids were nothing new at the time, the Vikings refined the practice to a science through their shipbuilding, tactics and training. Unlike other raiders, the Vikings made a lasting impact on the face of Europe. During the Viking age, their expeditions, frequently combining raiding and trading, penetrated most of the old Frankish empire, the British Isles, the Baltic region, Russia, and both Muslim and Christian Iberia. Many served as mercenaries, and the famed Varangian Guard, serving the Emperor of Constantinople, was drawn principally of Scandinavian warriors.