The economic and social history of the Indian Ocean world has never received the same attention as that of the Atlantic on grounds of ethnocentricity as well as a paucity of documentation. Both the substance of the essays in the present volume (including the excellent introduction by Robert Harms) and their rich bibliographic references indicate that considerable progress has been made over the last decades in righting this historiographic imbalance. The contributors focus on three issues: the trajectory of Indian Ocean slavery and slave-trading in relation to global economic change; the social dynamics of slavery and linked forms of dependence within local communities; and, the ineffectualness of both European and Islamic abolitionism in and around the region.

As several authors here note, during the nineteenth-century ‘age of abolition’, when the Atlantic slave-system came to an end, slavery and slave-trading in the Indian Ocean not only flourished but increased. None of the authors take up the well-worn slave trade ‘numbers game’ in any detail, although Gwyn Campbell asserts that the totality of slaves leaving Africa by these eastern maritime routes ‘over the centuries’ probably ‘well exceeded the 10 million or 12 million that landed in the Americas’ (p. 32). Instead, several contributions point to new enterprises that created demands for slaves, particularly clove and other plantations on the island of Zanzibar and its coastal domains, as well pearl-fishing and date-growing in the Red Sea and Persian Gulf. For the latter regions, Janet Ewald and Matthew Hopper provide valuable new information on the employment of African slaves and freedmen as sailors, pearl divers, and date plantation laborers. Hopper usefully documents the rise and fall in demand for Gulf pearls and dates on the world market, although, as several other authors here, he spends a bit too much time beating on straw men, in this case advocates of a timeless, non-economic ‘Islamic’ slavery system.

The more extensive social histories of slavery and related dependencies in this volume all stress how different it was from the Atlantic plantation experience, with Islamic encouragement of conversion and manumission playing some role. Plantation workers and pearl divers were the slaves least likely to benefit from such pious actions but many captives were brought into urban households and used in occupations, especially commerce, which provided opportunities for social mobility (including manumission). Abdul Sheriff presents an extended account of one such prosperous ex-slave merchant in Dubai, whose eventual bankruptcy and legal difficulties produced a very large paper trail. It is difficult to generalize from a single case, but ‘The Strange Career of Sultan bin Aman’ shows not only the possibilities of advancement for freedmen but also the potentially dangerous ambiguities of their necessary patron-client ties to the families of former masters. Thomas McDow was able to unearth a more representative archive of manumitted slaves in surviving ‘contracts and business deeds in Zanzibar’, which not only identifies such individuals but also tell us about their property ownership and general affairs. McDow does not make any statistical use of these documents and his chapter ranges over wide issues using many more traditional European documents and secondary references to African oral sources, but he does provide enough details on both manumission and its effects so as to suggest that still further research could be pursued using the methods he introduces.

European abolition gets fairly short shrift here because it has already been well-established that both the British Navy's efforts to end the slave trade and the initial efforts of British and German colonial regimes did not effect much change in systems of commerce and servitude operated, unlike those in the Atlantic, by local groups on their own terms. Even some Europeans, most notably the French on Mascarene island of Réunion, used what McDow calls ‘insincere manumission’ to obtain indentured plantation labor. Richard Allen, a leading historian of European slave-trading and indentured labor in the Indian Ocean contributes a very informative chapter on the latter topic but does not come to any clear conclusion as to whether it constituted ‘a new system of slavery’.

Two chapters on the Royal Navy's anti-slave trade patrols of the Indian Ocean confirm both their limited effectiveness and an apparent lack of interest in the slaves being freed as opposed to the traders being punished. Lindsay Doulton spends a bit too much time refuting ‘the rhetoric of abolitionism’ but offers some valuable accounts of how naval personnel viewed the people they rescued. Detailed analysis by Mandana Limbert of the documents from one capture provides excellent insight into the organization of the trade and can, perhaps, be replicated more widely. Bernard Freamon and Gervase Clarence-Smith each contribute an essay on Islamic abolitionism but neither makes a strong case for the power or pervasiveness of such discourse in the nineteenth or twentieth centuries, even among Islamic modernists. Freamon instead concludes that concerns of this kind ‘should occupy the attention of modern Muslim minds’ (p. 74, emphasis added).