Following some ten years as a practicing lawyer and consultant, Kirstyn Inglis has been researching the evolving legal practice of EU enlargement for over ten years. This book, succinctly, introduces this evolving practice, covering transitional arrangements in accession treaties, the Treaty of Lisbon, recent European Court case law, the specific governance challenge of incorporating Bulgaria and Romania and the strategy for future enlargements to bring in the Western Balkans and Turkey. In part two, the examples of the environment and the agri-food acquis are explored, including the analysis of the transitional arrangements in practice. Overall, the diversity and complexity of the pre-accession and post-accession challenge of enlargement becomes apparent, as do key challenges for the evolution of the acquis communautaire in an enlarging Union at a time when Croatia is waiting to sign its own accession treaty.