Humans are, in fundamental ways, a migratory species, more so than any other land mammal. For most of our existence , we were all nomads, and some of us still are. Houses and permanent settlements are a relatively late development - dating back little more than twelve thousand years. Borders and passports are much more recent. From the Neanderthals, Alexander the Great, Christopher Columbus and Pocahontas to the African slave trade, Fu Manchu, and Barack Obama, Migrants shows us that it is only by understa