With his textbook, International Migration Law, Vincent Chetail (Professor of International Law, Head of the International Law Department and Director of the Global Migration Centre at the Graduate Institute of International and Development Studies, Geneva) offers a much-needed reference book for all – scholars, students, practitioners, and policymakers – who work on migration and mobility at the international and regional levels. As we know, migration is a natural and global phenomenon that characterizes the essence of human presence on earth; yet, it is more visible in a globalized world, and more sensitive politically. Meanwhile, international migration law is too frequently denied or discarded. Of course, it does exist and provides a receptacle of binding duties for States. The corpus of legal rules that deals with migration is particularly important and significant. As Chetail recalls in the book’s introduction, the term ‘international migration law’ was used by Louis Varlez in 1927 in his course at The Hague Academy, and by Richard Plender as the title of a text first published in 1972, with a second edition in 1988 (p 10). Subsequently, the academic literature has developed in a rather piecemeal manner alongside the different branches of international law. It has thus needed a genuine masterwork to present in a complete and inclusive manner the various international norms that govern the movement of persons between States, whether they are countries of emigration, transit, or immigration.