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 Age
In Scandinavia, the Viking age is considered to have ended with the establishment of royal authority in the Scandinavian countries and the establishment of Christianity as the dominant religion. The date is usually put somewhere in the early 11th century in all three Scandinavian countries. The end of the Viking era in Norway is marked by the Battle of Stiklestad in 1030. Although Olafr Haraldsson's (later known as Olav the Holy) army lost the battle, Christianity spread, partly on the strength of rumours of miraculous signs after his death. Norwegians would no longer be called Vikings. In Sweden, the reign of king Olov Skötkonung ( 995–1020) is considered to be the transition from the Viking age to the Middle Ages, because he was the first Christian king of the Swedes, and he is associated with a growing influence of the church in what is today southwestern and central Sweden.