This work offers a jurisprudential analysis of internal and external differentiated integration in European Union law. It first examines concrete examples of differentiation, in particular economic and monetary integration as well as the integration of Norway and Switzerland. In a subsequent analysis, different legal mechanisms of differentiated integration are categorized and the compatibility of differentiated integration with the principles of Union law is examined. Finally, an attempt is made to provide an overall view, which in particular also addresses the governability of differentiated integration.
