For most of human history, the seas and oceans have been the main means of long-distance trade and communication between peoples -- for the spread of ideas and religion as well as commerce. This book traces the history of human movement and interaction around and across the world's greatest bodies of water, charting our relationship with the oceans from the time of the first voyagers. David Abulafia begins with the earliest of seafaring societies -- the Polynesians of the Pacific, the possessors of intuitive navigational skills long before the invention of the compass, who by the first century were trading between their far-flung islands. By the seventh century, trading routes stretched from the coasts of Arabia and Africa to southern China and Japan, bringing together the Indian Ocean and the western Pacific and linking half the world through the international spice trade. In the Atlantic, centuries before the little kingdom of Portugal carved out its powerful, seaborne empire, many peoples sought new lands across the sea -- the Bretons, the Frisians and, most notably, the Vikings, now known to be the first Europeans to reach North America. As Portuguese supremacy dwindled in the late sixteenth century, the Spanish, the Dutch and then the British each successively ruled the waves. Following merchants, explorers, pirates, cartographers and travellers in their quests for spices, gold, ivory, slaves, lands for settlement and knowledge of what lay beyond, Abulafia has created an extraordinary narrative of humanity and the oceans.