Book excerpt: This volume suggests new, theoretically informed approaches for historians and social scientists to engage with the policy of enlargement – across rounds and in all its diversity. It follows three approaches: first tracing Longue Durée developments; second, investigating enlargement Beyond the Road to Membership; and third, exploring the Entangled Exchanges and synergies between the EC/EU and its outside. It attempts to properly historicise the process of enlargement with contributions from historians, social scientists and a legal scholar exemplifying suggested approaches and theoretical reflections from the various disciplines.