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.
History of Denmark
With the beginning of the Viking Age in the 9th century, the prehistoric period in Denmark ends. The Danish people were among those known as Vikings, during the 8th–11th centuries. Viking explorers first discovered and settled in Iceland in the 9th century, on their way from the Faroe Islands. From there, Greenland and Vinland (probably Newfoundland) were also settled. Utilizing their great skills in shipbuilding and navigation they raided and conquered parts of France and the British Isles.
They also excelled in trading along the coasts and rivers of Europe, running trade routes from Greenland in the north to Constantinople in the south via Russian and Ukrainian rivers, most notably along the River Dnieper and via Kiev, then being the capital of Kiev Rus. The Danish Vikings were most active in Britain, Ireland, France, Spain, Portugal and Italy where they raided, conquered and settled (their earliest settlements included sites in the Danelaw, Ireland and Normandy). The Danelaw encompassed the Northeastern half of what now constitutes England, where Danes settled and Danish law and rule prevailed. Prior to this time, England consisted of approximately seven independent Anglo-Saxon kingdoms. The Danes conquered (terminated) all of these except for the kingdom of Wessex. Alfred the Great, king of Wessex, emerged from these trials as the sole remaining English king, and thereby as the first English Monarch.