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.
Vikings
The majority of runic inscriptions from the Viking period are found in Sweden and date from the 11th century. The oldest stone with runic inscriptions was found in Norway and dates to the 4th century, suggesting that runic inscriptions pre-date the Viking period. Many runestones in Scandinavia record the names of participants in Viking expeditions, such as the Kjula runestone that tells of extensive warfare in Western Europe and the Turinge Runestone, which tells of a war band in Eastern Europe. Other runestones mention men who died on Viking expeditions. Among them are around 25 Ingvar runestones in the Mälardalen district of Sweden, erected to commemorate members of a disastrous expedition into present-day Russia in the early 11th century. Runestones are important sources in the study of Norse society and early medieval Scandinavia, not only of the Viking segment of the population.