All too often religion is largely ignored as a driver of identity formation in the European context, whereas in reality Christian Churches are central players in European identity formation at the national and continental level. Christian Churches in European Integration challenges this tendency, highlighting the position of churches as important identity formers and actors in civil society. Analysing the role of Churches in engaging with two specific EU issues – that of EU treaty reform and ongoing debates about immigration and asylum policy – the author argues that Churches are unique participants in European integration. Establishing a comprehensive view of Christian Churches as having a vital role to play in European integration, this book offers a substantial and provocative contribution both to our understanding of the European Union and the broader question of how religious and state institutions interact with one another.