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
The first Viking raids began between 790 and 800 along the coasts of western France. They were carried out primarily in the summer, as the Vikings wintered in Scandinavia. Several coastal areas were lost to Francia during the reign of Louis the Pious (814–840). But the Vikings took advantage of the quarrels in the royal family caused after the death of Louis the Pious to settle their first colony in the south-west (Gascony) of the kingdom of Francia, which was more or less abandoned by the Frankish kings after their two defeats at Roncevaux. The incursions in 841 caused severe damage to Rouen and Jumièges. The Viking attackers sought to capture the treasures stored at monasteries, easy prey given the monks' lack of defensive capacity. In 845 an expedition up the Seine reached Paris. The presence of Carolingian "deniers" of "ca" 847, found in 1871 among a hoard at Mullaghboden, County Limerick, where coins were neither minted nor normally used in trade, probably represents booty from the raids of 843–846. After 851, Vikings began to stay in the lower Seine valley for the winter. Twice more in the 860s Vikings rowed to Paris, leaving only when they acquired sufficient loot or bribes from the Carolingian rulers.