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.
Viking expansion
Our knowledge of Vikings in Iberia is mainly based on written accounts, many of which are much later than the events they purport to describe, and often also ambiguous about the origins or ethnicity of the raiders they mention. A little possible archaeological evidence has come to light, but research in this area is ongoing. Viking activity in the Iberian peninsula seems to have begun around the mid-ninth century as an extension of their raids on and establishment of bases in Frankia in the earlier ninth century, but although Vikings may have over-wintered there, there is as yet no evidence for trading or settlement.