The object of this chapter is to persuade those who need persuading, or are willing to be persuaded, that the concept of the nation that lies at the heart of all forms of nationalism was widespread long before the eighteenth century. This concept, as I understand, is the idea or assumption that nations are natural, given, objectively existing human communities, each of which is assumed, generally in a vague and unreasoned way, not only to have its own common culture, myths, history, and destiny, but also to be a political community with a right to what is now called self-determination. This definition is derived from that given by Anthony Smith in 1973, which lit up the subject for me in a flash and still seems to me a masterpiece of clarity. He was setting out what he saw as the basic doctrine of nationalism, so that his definition was in effect a nationalist one. That seems to me inevitable, because nations are hard to identify and define except in terms of the beliefs about them held by those who think of them as real objective entities. I shall refer to this way of thinking about nations as ‘nationalist’, but that does not mean that I suggest that all who thought like this in the past had the same aims and policies as have those who are called nationalist today.