Barry Cunliffe looks at the development of seafaring on the Mediterranean and the Atlantic, two contrasting seas; the Mediterranean without a significant tide, enclosed and soon to become familiar, the Atlantic with its frightening tidal ranges, an ocean without end. We begin with the Middle Palaeolithic hunter-gatherers in the eastern Mediterranean building simple vessels to make their remarkable crossing to Crete and we end in the early years of the sixteenth century with sailors from Spain, Portugal and England establishing the limits of the ocean from Labrador to Patagonia. The message is that the contest between humans and the sea has been a driving force, perhaps the driving force, in human history.