Race is a real and powerful force and one he has spent his adult life trying to understand, says Anglo-Nigerian historian, writer and producer, David Olusoga. He talks us through five books on the tragedy of slavery—from the horrors of the gulag, to the plantations of Virginia, to the Islamic slave trade.

Harvard professor and Pulitzer prize-winning historian Bernard Bailyn recommends reading on three centuries of empire, conflict and slave trading between the Americas, Europe and Africa