Any take on the politics of monetary policy starts from the recognition that a de facto separation of central banking from democratic processes is impossible to achieve fully in a democratic society, even if it is mandated de iure in the form of central bank independence. This implies that monetary authorities, like the European Central Bank (ECB), can and should be evaluated not only in terms of how well they perform according to their own mandates, but also in terms of wider normative criteria of democratic legitimation. This chapter thus submits that to make sense of the politics of Europe’s monetary union we need to focus on the multi-dimensional issue of the legitimacy of the ECB.