father, nevertheless by 821 the Vikings had sailed round Brittany and sacked monasteries in the islands of Noirmoutier and Rhé. From 814-833 attacks were almost entirely confined to these districts, and it is possible that these Vikings had their winter quarters in Ireland, where they were specially active at this time. At any rate it was to Wexford that one of these fleets returned in 820. The later years of Louis's reign (from 834) were troubled ones. The Empire was weakened by the Emperor's differences with his sons, and the Vikings had laid a firm hold on Frisia. They were attracted by its rich trade and more especially by the wealth of Dorestad, one of the most important trading cities of the Empire. Before the death of the Emperor in 840, Dorestad had been four times ravaged and the Vikings had sailed up the chief rivers, burning both Utrecht and Antwerp. Their success was the more rapid owing to the disloyalty of the Frisians themselves and possibly to help given them by Harold and his brother Roric, but the exact attitude of these princes and of the Danish king himself toward the raiders it is difficult to determine. There are rather too many protests of innocence on the part of Horic for us to believe in their entire genuineness.
After 840 the quarrels between the heirs of Louis the Pious laid Western Europe open to attack even more than it had been hitherto. In that year the Vikings sailed up the Seine for the first time as far as Rouen, while in 843 they appeared for the first time on the Loire. Here they were helped by the quarrels over the Aquitanian succession, and it is said that pilots, lent by Count Lambert, steered them up the Loire. They then took up their winter quarters on the island of Noirmoutier, where they seemed determined to make a permanent settlement. The invasions in France had reached the same stage of development to which we have already traced them in England and Ireland. It is in connexion with this expedition that we have one of the rare indications of the actual home of the invaders. They are called "Westfaldingi," and must therefore have come from the Norwegian district of Vestfold, which, as we have seen, formed part of the Danish kingdom about this time.
In 843 the Northmen advanced a stage further south. Sailing past Bordeaux they ravaged the upper basin of the Garonne. In the next year they visited Spain. Repelled by the bold defence of the Asturians, they sailed down the west coast of the peninsula and in September appeared before Lisbon. The Moors offered a stout resistance and the Vikings moved on to Cadiz, whence they ravaged the province of Sidonia in southern Andalusia. Penetrating as far as Seville, they captured that city, with the exception of its citadel, and raided Cordova. In the end they were out-generalled by the Musulmans and forced to retreat with heavy loss. Taking to their ships once more they ravaged the coast as far as Lisbon, and returned to the Gironde before the end of the year. It was probably on this expedition that some of the Vikings
