Based on four years of embedded observation in the cabinet of a European Commissioner, this book develops a sociology of international political work. Empirically, it offers an insider’s chronicle of the European Union between 2015 and 2019. The analysis traces the successes and failures of Commissioner Pierre Moscovici and his team on five issues that defined European politics between 2015 and 2019: the Greek crisis, budgetary disputes with Spain and Portugal, the rise of populism in Italy, the reform of the eurozone, and the fight against tax evasion. The aim is not to ascertain whether the Commission’s policy was good or bad, but to understand how political work is done in a European Union where the ‘spectacle of power’ is blurred by 24 official languages, 28 national histories, a powerful technocracy, and sometimes opaque institutions. As a life-long socialist politician and former French finance minister, Pierre Moscovici was perhaps the most intensely political character in Jean-Claude Juncker’s self-styled ‘Political Commission’. Brandishing his leftist identity, rejecting technocratic talk, he surrounded himself with staffers sharing his ambition – but also critical of his actions. Shadowing them from the corridors of the Berlaymont, the seat of the European Commission, to Washington and Athens, The Political Commissioner throws light on the partisan struggles that shaped the Juncker Commission, tensions with the Eurogroup and the Parliament, and recurring conflicts with the Member States. It also shows how political staffers operate informally and in their interaction with the media and civil servants, as they craft and sell public policies to the public. In this ethnographic narrative, French politics is never far away. Decoding the European policy of a French, Socialist Commissioner, first under Francois Hollande and then Emmanuel Macron, the book investigates the dynamics that sometimes bring Brussels and Paris together, sometimes set them apart. Transformations in Governance is a major academic book series from Oxford University Press. It is designed to accommodate the impressive growth of research in comparative politics, international relations, public policy, federalism, and environmental and urban studies concerned with the dispersion of authority from central states to supranational institutions, subnational governments, and public-private networks. It brings together work that advances our understanding of the organization, causes, and consequences of multilevel and complex governance. The series is selective, containing annually a small number of books of exceptionally high quality by leading and emerging scholars. The series is edited by Liesbet Hooghe and Gary Marks of the University of North Carolina, Chapel Hill, and Walter Mattli of the University of Oxford.