Book excerpt: This book examines 'The Espoo Convention on Environmental Impact Assessment in a Transboundary Context', which celebrates the twentieth anniversary of its adoption in 2011, and its 'Kiev Protocol on Strategic Environmental Assessment' which came into force in July 2010. In addition to contributing to international environmental law, the Convention has prompted significant changes to European environmental law. The chapters in this collection explain the role of transboundary environmental impact assessment in international and European law, and explore the relationship between international and European law in the context of potential application of the Convention. They also examine examples of the Convention in practice, and consider the potential application of the Protocol. While the focus of the book is on the situation in the European Union, reference is made to the relationship between EU and non-EU member states, notably in connection with important cases in the Arctic, the Danube Delta and the Baltic Sea.