David Fieldhouse suggested this book. In writing it, I have strayed far from my expertise as a documentary historian. John Sutton is partly to blame for that because he first interested me in African prehistory through his lectures at Dar es Salaam. David Phillipson kindly read and commented on my initial typescript, as did John Lonsdale, who has taught me so much. John Alexander and Timothy Insoll helped with books.
In this new edition, I have recast the final chapters, now current to early 2016, extensively revised the sections on prehistory and the Atlantic slave trade, and made substantial changes to take account of recent scholarship on other periods. In doing so, I have relied heavily on the magnificent resources of the Cambridge University Library and have been grateful for the support and companionship of the members of my College.