Privateering was legal whereas piracy was illegal. That much everyone knows. But what exactly was privateering? Answering this question turns out to depend not so much on the relationship between privateering and piracy as on the relationship between privateering and other forms of maritime raiding that had been considered legal long before the word ‘privateering’, or the practice it denoted, came into existence. This book clarifies all these relationships and explains how privateering emerged as a new legal category in the late sixteenth and early seventeenth centuries. The subject is approached from a British perspective, in the light of developments elsewhere, including the movement towards a new understanding of the law regulating relations between nations.