The north and east of the island were most affected. During the first 40 years, the raids were conducted by small, mobile Viking groups. By 830, the groups consisted of large fleets of Viking ships. From 840, the Vikings began establishing permanent bases at the coasts.
https://en.wikipedia.org/wiki/Viking_Age
Scandinavians were certainly not the only people of their era to raid and pillage their neighbors, but they did it with greater frequency and a brutal efficiency not seen in other cultures. What drove them go i viking? There are several competing theories, and no single reason probably fully explains it.
http://history.howstuffworks.com/historical-figures/viking4.htm
This first raid is recorded in the Anglo-Saxon Chronicle. It was the start of a fierce struggle between English and Vikings. The English called the Viking invaders 'Danes' but they came from Norway as well as Denmark. Norwegian Vikings or 'Norse' sailed to Scotland, where they made settlements in the north and on the Orkney and Shetland islands. Vikings also settled on the Isle of Man. Vikings raided Wales, but few made homes there.
http://www.bbc.co.uk/schools/primaryhistory/vikings/who_were_the_vikings/
Due to their naval and military superiority, the Viking raids were very devastating to Northern Europe. The first raid occurred in the year 793 against the monastery of Lindisfarne on England's east coast. This triggered a series of events commonly related to religion Why did God send these people against us?
http://www.medievality.com/viking-raids.html
The Viking Age settlements in Greenland were established in the sheltered fjords of the southern and western coast. They settled in three separate areas along approximately 650 kilometres (350 nautical miles; 400 statute miles) of the western coast.
https://en.wikipedia.org/wiki/Viking_Age
First, they had a very important need to rise up the social ladder. Since they didn't believe in the afterlife, they knew that their name and reputation were extremely important to be remembered. Therefore, they had to rise above everyone else by combat. Vikings adored combat and saw it as a healthy way of life.
http://www.medievality.com/viking-raids.html
Scandinavians had settled Iceland early on in the Age of Vikings. A Viking with the name Erik the Red was exiled from Iceland upon his conviction for murder. Hearing tales of land to the west, he set out with a boat full of men and supplies and found Greenland, where a settlement was established.
http://history.howstuffworks.com/historical-figures/viking4.htm
The Vikings who invaded western and eastern Europe were chiefly pagans from Denmark, Norway and Sweden. They also settled in the Faroe Islands, Ireland, Iceland, Scotland (Caithness, the Hebrides and the Northern Isles), Greenland, and Canada.
https://en.wikipedia.org/wiki/Viking_Age
It is the period of history when Scandinavian Norsemen explored Europe by its seas and rivers for trade, raids and conquest. In this period, the Norsemen also settled in Norse Greenland, Newfoundland, and present-day Faroe Islands, Iceland, Normandy, Scotland, England, Ukraine, Ireland, Russia and Anatolia.
https://en.wikipedia.org/wiki/Viking_Age
The Vikings came from three countries of Scandinavia: Denmark, Norway and Sweden. The name 'Viking' comes from a language called 'Old Norse' and means 'a pirate raid'. People who went off raiding in ships were said to be 'going Viking'. The Viking age in European history was about AD 700 to 1100.
http://www.bbc.co.uk/schools/primaryhistory/vikings/who_were_the_vikings/
when did the vikings raids begin
The Vikings Raids began about AD 700 to 1,100.