Vikings in Iberia
The first incursion of the Vikings in Iberia has been characterised as 'probably the most significant episode of the whole period of Viking activity in the South'. It is mentioned in "Annales Bertiniani", and dated August 844, when a group from a plundering expedition entered the Garonne and reached Galicia. Despite storm damage, some proceeded to South-West Spain. This account is consistent with several later, but independent sources in Latin and Arabic. In particular, the late ninth- or early tenth-century "Chronicle of Alfonso III" adds that after plundering a number of coastal villages they were ultimately repulsed in the vicinity of "Farum Brecantium" (i.e. the Tower of Hercules). Ramiro I of Asturias gathered troops in Galicia and Asturia for the counter-attack. After the Asturian victory, the Vikings continued their voyage in direction of Lisbon. While some authors consider that the reliability of this chronicle is open to doubt, others consider that other local chronicles confirm the arrival of the Norsemen.
Ímar
The earliest recorded Viking raids in Ireland occurred in 795. Over time, these raids increased in intensity, and they overwintered in Ireland for the first time in 840–841. In 841 a longphort was constructed at (Irish for "hurdled ford"), a site which would later develop into the city of Dublin. Longphorts were also established at other sites around Ireland, some of which developed into larger Viking settlements over time. The Viking population in Ireland was boosted in 851 with the arrival of a large group known as "dark foreigners" – a contentious term used to refer to the newly arrived Vikings, as opposed to the "fair foreigners", i.e. the Viking population which was resident in arrival prior to this influx. A kingdom in Viking Scotland was established by the mid ninth-century, and it exerted control over some of the Vikings in Ireland. By 853 a separate kingdom of Dublin had been set up which claimed control over all the Vikings in Ireland.