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. From the earliest forays of peoples in hand-hewn canoes through uncharted waters to the routes now taken daily by supertankers in their thousands, The Boundless Sea shows how maritime networks came to form a continuum of interaction and interconnection across the globe: 90 per cent of global trade is still conducted by sea. This is history of the grandest scale and scope, and from a bracingly different perspective - not, as in most global histories, from the land, but from the boundless seas.