This is a story of saints and spies, of anglers and pirates, traders and marauders - and of how their wild and daring journeys across the North Sea built the world we know. When the Roman Empire retreated, northern Europe was a barbarian outpost at the very edge of everything. A thousand years later, it was the heart of global empires and the home of science, art, enlightenment and money. We owe this transformation to the tides and storms of the North Sea. Boats carried food and raw materials, but also new ideas and information. The seafarers raided, ruined and killed, but they also settled and coupled. With them they brought new tastes and technologies - books, science, clothes, paintings and machines. Drawing on an astonishing breadth of learning and packed with human stories and revelations, this is the epic drama of how we came to be who we are.