In recent years, research on migrations has had to deal with profound transformations in the definition of borders, in the context of the enlargement of the European Union. The aim of this book is to tackle both the institutional and the regulatory aspects of migration and border policies developed by the European Union and its Member States. The idea is to create a research framework to examine the responses offered by the migration systems, as well as the emergence of a definition of the European Union's external border. The book collect the main contributions made at the joint initiative seminar by GRITIM-UPF at the Universitat Pompeu Fabra (Barcelona, Spain) and the Migration Programme of CIDOB held on 10th September 2009 entitled “Migrations and Borders in the European Union”. The compilation cover three dimensions – the conceptual, the practical and the political – and is focused on a range of issues, including border control and securitisation, the externalisation of migration policies, the institutional discourse of the EU on the subject of border management or the theoretical debates on the concepts of migration and borders.