Blackburn opens by describing the system that was about to come under attack. By 1770 New World slavery was not a leftover from an older order but something new. The sugar estate, with its calibrated labour and mechanical rhythms, half anticipated the factory, and the planter was an entrepreneur who could sit out war or slump on his estate's own subsistence and then expand hard when markets beckoned.

He separates this from the ancillary slavery of the early Spanish empire, where wealth came from conquering and taxing indigenous populations, and ties the newer form's growth to European appetite: sugar, tobacco and cotton were small pleasures that pulled ordinary people into a money economy and paid useful revenue to states.

The arithmetic is stark. Some six million captives landed in the Americas during the eighteenth century against roughly a million Europeans, with mortality so severe that a trade on that scale was needed merely to keep numbers from falling.