What gave Columbus the confidence in 1492 to set out across the Atlantic Ocean? It would be convenient to believe that Columbus and his men were uniquely courageous. A more reasonable explanation, however, is that Columbus was heir to a body of knowledge about seas and ships acquired at great cost over many centuries. Fish on Friday tells a new story of the discovery of America. In Brian Fagan"s view, that discovery is the product of the long sweep of history: the spread of Christianity and the radical cultural changes it brought to Europe, the interaction of economic necessity with a changing climate, and generations of unknown fishermen who explored the North Atlantic in the centuries before Columbus. Encompassing ancient mythology, medieval religion, boatbuilding, commerce, and cutting-edge climate science, this dazzling and wide-ranging book shows the intricate tapestry of history in all its fascinating, astonishing complexity.