Norway
From the 8th to the 10th century, the wider Scandinavian region was the source of Vikings. The looting of the monastery at Lindisfarne in Northeast England in 793 by Norse people has long been regarded as the event which marked the beginning of the Viking Age. This age was characterised by expansion and emigration by Viking seafarers. They colonised, raided, and traded in all parts of Europe. Norwegian Viking explorers first discovered Iceland by accident in the 9th century when heading for the Faroe Islands, and eventually came across Vinland, known today as Newfoundland, in Canada. The Vikings from Norway were most active in the northern and western British Isles and eastern North America isles.
Kingdom of the Isles
Prior to the Viking incursions the southern Hebrides formed part of the Gaelic kingdom of (or Dalriada). North of , the Inner and Outer Hebrides were nominally under Pictish control although the historical record is sparse. According to Ó Corráin (1998) "when and how the Vikings conquered and occupied the Isles is unknown, perhaps unknowable", although from 793 onwards repeated raids by Vikings on the British Isles are recorded. "All the islands of Britain" were devastated in 794 with Iona being sacked in 802 and 806. Various named Viking leaders, who were probably based in Scotland, appear in the Irish annals: in 837, in 845 and in 847. Another early reference to the Norse presence in the Irish records is that there was a king of "Viking Scotland" whose heir, , took an army to Ireland in 848.