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.
Kingdom of Dublin
Vikings invaded the territory around Dublin in the 9th century, establishing the Norse Kingdom of Dublin, the earliest and longest-lasting Norse kingdom in Ireland. Its territory corresponded to most of present-day County Dublin. The Norse referred to the kingdom as "Dyflin", which is derived . The first reference to the Vikings comes from the "Annals of Ulster" and the first entry for 841 CE reads: "Pagans still on Lough Neagh". It is from this date onward that historians get references to ship fortresses or longphorts being established in Ireland. It may be safe to assume that the Vikings first over-wintered in 840–841 CE. The actual location of the longphort of Dublin is still a hotly debated issue. Norse rulers of Dublin were often co-kings, and occasionally also Kings of Jórvík in what is now Yorkshire. Under their rule, Dublin became the biggest slave port in Western Europe.