Privateering was a form of legal private warfare at sea in which individuals who possessed suitable ships took the opportunity offered by a war to plunder enemy commerce. In this study of privateering during the Elizabethan war with Spain, which was originally published in 1966, Dr Andrews shows that it was closely connected with trade, in particular having a stimulating effect on oceanic commerce and that it was at the time the main form of English maritime warfare. Dr Andrews begins with an account of how privateering became legal and how it was organised. He then examines the various types of venture, describing the sort of people who took part and showing how profitable it was for some, particularly the bigger merchants and the professional seamen. Two contemporary narratives are included. Finally, Dr Andrews studies the role privateering played in overseas expansion.