The compilation of papers in the present volume of the Review is based on lectures presented during the sixteenth University of Eastern Finland – United Nations Environment Programme Course on Multilateral Environmental Agreements (MEAs), held from 14 to 24 October 2019 in Siena, Italy. The publication is aimed at equipping present and future negotiators of MEAs with information in the area of international environmental law-making, including the experience of others, in order to improve the impact and implementation of these key treaties. The ultimate aim is to strengthen and build environmental negotiation capacity and governance worldwide. It is intended that the current Review will provide practical guidance, professional perspective and historical background for decision-makers, diplomats, negotiators, practitioners, researchers, students, teachers and different stakeholders who work with international environmental law-making and diplomacy. The Review encompasses different approaches in this field, including international environmental law and governance, international environmental law-making, environmental empowerment, and the enhancement of sustainable development generally. The special themes of the Reviews bring naturally their own approaches and special questions into the publication.