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.
Ólchobar mac Cináeda
Late in 848 Ólchobar is said to have set up a camp from which the Vikings at Cork were blockaded. The result of this siege is nowhere recorded. This is the first mention of the Vikings at Cork. They are not heard of again until 865. It has been suggested that these several campaigns against Vikings were a coordinated effort by the chief Irish kings.