The best way to approach this book is as a starting point. Allen’s goal is not only to prove that European slaving took place in the Indian Ocean between 1500 – 1850, but that it was intimately related to the more popularly studied transatlantic slave trade. He proposes a world system of slavery. The book is strongest when Allen is exposing the European role in the Indian Ocean’s slave trade, and he resists the trap of simply recounting what he found in his sources, though he does generate an amazing amount of statistical analysis. He proves his argument most convincingly when he traces the evolution of abolitionist thought in the Indian Ocean, linking it to similar developments in Europe. Allen is the first to admit that there is much work to be done on this subject, but this book does a great job of opening the door to future scholarship on the link between transatlantic and Indian Ocean slavery.