europe as a whole might have adopted one of several political forms. These included theocratic federation, of which the Holy Roman Empire was a waning example; trading networks like the Hanseatic League, or sets of city-states (though these took too little account of power based on land-holding); feudalism, which was however being pressed out into centralised states; and political empire (Wesson 1978:1; Tilly 1975:31). Most of the large populations of the world were organised into empires and the empires had been growing in size for millennia (Taagepera 1978). But Europe's real empires were later creations, the overseas possessions of the individual states. After the fall of Rome no empire was successfully built within Europe, from the time of Charlemagne to the Habsburgs and beyond. The ambitions of Charles V failed in the 1550s, the ambitions of his son Philip II failed, and the Habsburgs failed again in the Thirty Years War, when Gustavus Adolphus, subsidised by Richelieu in one of those cross-alliances that came to typify European rivalries, was able to thwart them.

Europe instead became a single system of states in which change in one cell affected the others. This is as crucial to understanding long-run economic development as it is to explaining the pattern of the industrial world that emerged in the nineteenth century. Certainly Europe neither modernised nor industrialised uniformly.