Five hundred years ago Europe was something of a backwater. Since the fall of Rome a thousand years before, the continent had broken up into a jigsaw of small territories, often at war with each other. The real powerhouses – of intellectual inquiry, technology and trade – lay elsewhere, in China, India and the Muslim world. Across the Atlantic, in the Americas, there thrived civilizations undreamt of by Europeans. But from around 1450 the balance started to shift, as Europe began to assert itself on the world stage.