The entire land surface of this planet, with the single exception of Antarctica, is now divided for purposes of government into territories known as national states. This is a relatively recent development in human history. Only two hundred years ago, there were fewer than 20 states with the shape and character that we should now recognize as deserving description as national states, with the rest of the world being divided between a host of very small principalities and city-states, a few untidy empires, and large areas that were the home of tribal communities who lived without ﬁxed territorial boundaries. By 1945 there were 51 national states and by 2000, following the virtual end of colonial empires, there were 192. Today the only relics of empire are a few miniscule territories such as Gibraltar, the Falkland Isles, Martinique and Guadeloupe. The transformation has come about largely because the doctrine of nationalism has both triumphed in Europe and been exported to the rest of the world.