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.
History of Ireland
The Vikings were expert sailors, who travelled in longships, and by the early 840s, had begun to establish settlements along the Irish coasts and to spend the winter months there. The longships were technologically advanced, allowing them to travel faster through the narrow rivers. Vikings founded settlements in several places; most famously in Dublin. Most of the settlements were near the water, allowing the Vikings to trade using their longships. Written accounts from this time (early to mid 840s) show that the Vikings were moving further inland to attack (often using rivers) and then retreating to their coastal headquarters.