Early Scandinavian Dublin
In the year 795 Vikings (probably of Norwegian origin) raided islands off the coast of Ireland for the first time. This was the beginning of a new phase of Irish history, which saw many native communities – particularly ecclesiastical ones – relocate themselves on the continent, or further afield in places like Iceland and the Faroe Islands, to escape the pagan marauders. For about two decades the invaders confined their activities to coastal settlements; raiding parties were generally small and there is no evidence that any of them wintered in Ireland during this early phase of "hit-and-run" activity. Typically the Vikings would arrive at a settlement without warning, plunder what goods and people they could – the people were usually sold as slaves, though notable personages were often held for ransom – before retreating to their Scandinavian or British bases. This period lasted from 795 until 813, after which there occurred a hiatus of eight years.
It is now thought that these early raids were launched directly from southwest Norway, and that during the period of calm (814–820) the Norwegian Vikings were occupied in northern Britain, laying the foundations of a new kingdom referred to in Irish sources as Laithlind (later Lochlainn). Laithlind was once thought to be in Norway but it is now identified with Viking settlements in the British Isles, especially those in Scotland and the Isle of Man.
Helge Ingstad
Helge Marcus Ingstad (30 December 1899 – 29 March 2001) was a Norwegian explorer. After mapping some Norse settlements, Ingstad and his wife Anne Stine, an archaeologist, in 1960 found remnants of a Viking settlement in L'Anse aux Meadows in the province of Newfoundland in Canada. They were thus the first to prove conclusively that the Icelandic Norsemen such as Leif Erickson had found a way across the Atlantic Ocean to North America, roughly 500 years before Christopher Columbus and John Cabot. He also thought that the mysterious disappearance of the Greenland Viking settlement in the 14/15th century could be explained by their emigration to North America.