Scandinavian Scotland refers to the period from the 8th to the 15th centuries during which Vikings and Norse settlers, mainly Norwegians and to a lesser extent other Scandinavians, and their descendants colonised parts of what is now the periphery of modern Scotland. Viking influence in the area commenced in the late 8th century, and hostility between the Scandinavian Earls of Orkney and the emerging thalassocracy of the Kingdom of the Isles, the rulers of Ireland, Dál Riata and Alba, and intervention by the crown of Norway were recurring themes.