The need to develop tools for the understanding of public finance has been highlighted by the financial crisis that broke in 2008. The research ambition of this project on the origins of political economy is to show that the intellectual history of public finance can generate such tools. Its main objective is to produce a monograph entitled *Public Debt and the Republic: Florentine Political Thought and Public Finance from 1470 to 1537*, which takes financial thought back to its roots, at a moment when the development of democratic institutions came to contradict the development of public credit. As such it also illuminates an understudied aspect of the political thought of the ‘Machiavellian Moment’, which redirected the tradition of classical Republicanism, thus defining one of the cornerstones of European modernity.This objective is achieved through:• exploitation of the Florentine archives. These preserve unique and unexplored materials which render feasible the in-depth reconstruction of the foundation of modern financial thought and practice• collaboration with the host institute. The Centre for the Study of the History of Political Thought (Queen Mary, University of London) hosts one of the largest concentrations of specialists in this field. The proposed investigation contributes to a central interdisciplinary research project of the Centre, on ‘Popular Sovereignty’.Undertaking the proposed project at the host institute allows the applicant to:• resume his European academic career after a five-semester hiatus researching and teaching in the USA and South Africa• further his career options in order to attain an academic position at a leading European institute• enhance his interdisciplinary skills, intertwining the history of ideas and the study of systems of administration• optimize his theoretical reflection, adept at both transnational and transhistorical analysis• acquire systematic knowledge of the financial culture of early modern Florence.