The cultural life of most of black Africa remained largely unaffected by European ideas until the last years of the nineteenth century, and most cultures began our own century with ways of life formed very little by direct contact with Europe. Direct trade with Europeans – and especially the slave trade – had structured the economies of many of the states of the West African coast and its hinterland from the middle of the seventeenth century onward, replacing the extensive gold trade that had existed at least since the Carthaginian empire in the second century BCE. By the early nineteenth century, as the slave trade went into decline, palm nut and groundnut oils had become major exports to Europe, and these were followed later by cocoa and coffee. But the direct colonization of the region began in earnest only in the later nineteenth century, and European administration of the whole of West Africa was only accomplished – after much resistance – when the Sokoto caliphate was conquered in 1903.