Vikings began raiding islands and monasteries on the Atlantic fringes of Europe in the 790s. The Irish Sea rapidly became one of their most productive hunting-grounds. Attacks, battles and destruction were accompanied by trade - in slaves, silver and fine objects. Vikings crossed and re-crossed the Irish Sea in search of land, wealth and power. Raids were followed by settlement, firstly in fortified camps, and later in towns, market enclaves and rural...