The recent financial crisis has highlighted conflicts of interests between socio-economic groups over economic policy. We use representations of economies as systems of interdependencies among productive sectors to conceptualize economic and political cleavages in terms of the contingent interplay of economic interdependencies between sectors and political conflict between the groups that represent those sectors. In doing so, we propose a structural and historical approach, which is illustrated with reference to three moments in the evolution of the eighteenth-century British fiscal system. Each of these case studies (the Beer Taxes of the 1690s, the Excise Crisis of 1733, and the Income Taxes of the Napoleonic Wars) reveals a different dimension of our approach. We close with some reflections on the conditions under which political conflict may be sustainable and provide directions for further inquiry.