By 830, the groups consisted of large fleets of Viking ships.

From 840, the Vikings began establishing permanent bases at the coasts.

Historical considerations In England, the beginning of the Viking Age is dated to 8 June 793, when Vikings destroyed the abbey on Lindisfarne, a center of learning that was famous across the continent.

After this interaction, the Irish experienced Viking forces for about 40 years.

The Vikings could sail through on the main river and branch off into different areas of the country.

During the first 40 years, the raids were conducted by small, mobile Viking groups.

The first Viking raids began between 790 and 800 along the coasts of western France.

After 851, Vikings began to stay in the lower Seine valley for the winter.

The Vikings did, however, settle in the south around St. David's, Haverfordwest, and Gower, among other places.

The beginning of the Viking Age in the British Isles is, however, often given as 793.

In 850 Vikings overwintered for the first time in England, on the island of Thanet, Kent.

A new wave of Norwegian Vikings appeared in England in 947 when Erik Bloodaxe captured York.

After a siege, the Vikings conquered Lisbon (at the time, the city was under Muslim rule and known as Al Ushbuna).

The Viking presence dwindled until 1066, when the invading Norsemen lost their final battle with the English at Stamford Bridge.

There was great but sporadic violence from the last decade of the 8th century on England s northern and eastern shores Viking raids continued on a small scale across coastal England.

To counter the threat, local rulers began to build large oared vessels, some with up to 30 pairs of oars, that were larger, faster and with higher sides than Viking ships.

The distribution of family names showing Scandinavian influence is still, as an analysis of names ending in son reveals, concentrated in the north and east, corresponding to areas of former Viking settlement.

The latter part comprising of the Low Countries, that technically became part of East Francia in 870, although it was effectively under the control of Vikings, who raided the largely defenceless Frisian and Frankish towns lying on the Frisian coast and along the rivers.