The five seas of the Atlantic - the Bay of Biscay, the Irish Sea, the English Canal, the North and Baltic Seas - have played a colossal role in the development of Europe. Archibald R. Lewis's book deals with the history of shipping and trade in the Nordic countries during the early Middle Ages. Analyzing historical chronicles, literary sources, as well as reports on archaeological research and numismatic finds in numerous treasures of the Viking Age, the professor examines the historical processes that resulted in the formation of new economic and cultural ties between the countries of Western Europe, Scandinavia, the Baltic and Kyiv Rus and the formation of modern European civilization.