Abstract
This chapter examines five of the European Union’s key institutions: the European Commission; the Council of ministers; the European Council; the European Parliament; and the European Court of Justice. It draws analogies to these institutions’ counterparts at the national level while also highlighting their distinct and unique features. It discusses the structures and formal powers of the five EU institutions and how they ‘squeeze’ influence out of their limited Treaty prerogatives. It concludes by explaining why these institutions matter in determining EU politics and policy more generally, focusing on three central themes: the extent to which the EU is an experiment in motion; the importance of power sharing and consensus; and the capacity of the EU structures to cope with the Union’s expanding size and scope.