The law of EU border controls is diverse and dynamic, involving multiple governance levels with distinct objectives. It addresses various 'control subjects' through a mix of soft and hard law sources. Dr Leandro Mancano evaluates how this diversity affects the constitutional compliance of EU border controls and explores the conditions necessary for the EU to remain an area without internal frontiers. By providing a comprehensive analysis of both external and internal border controls, and offering insights into the laws and practices of specific member states, this research addresses how to effectively manage or overcome the challenges posed by this heterogeneity within the EU legal framework. Ultimately, The Law of EU Border Controls: Constitutional Compliance and Conditions for an Area without Internal Frontiers highlights the impact of European integration on national sovereignty and enhances the understanding of EU border law as part of the unique EU legal system. It is an essential resource for academics and practitioners interested in migration and asylum law.