I am a professor of international law at the Graduate Institute of International and Development Studies in Geneva, working on issues of international law, global governance and law beyond the state. I am also a co-director of the Global Governance Centre there. At the same time, I am a Senior Research Fellow at the Institut Barcelona d’Estudis Internacionals (IBEI) and a fellow at the Hertie School of Governance, Berlin. Previously, I was ICREA research professor at the IBEI (currently on leave), a professor of international law at the Hertie School, a senior lecturer at the Law Department of the London School of Economics and Political Science, and a research fellow at Merton College (Oxford), New York University School of Law and the Max Planck Institute for Comparative Public Law and International Law in Heidelberg. I have also been a visiting professor of law at Harvard Law School. I hold a Ph.D. in law from the University of Heidelberg and a Diploma of European Law of the Academy of European Law in Florence, Italy. I am the author of Selbstverteidigung und kollektive Sicherheit (Self-defense and Collective Security, 2001) and of articles on the United Nations, hegemony in international law, and the legal order of global governance. My most recent book, Beyond Constitutionalism: The Pluralist Structure of Postnational Law (2010), was awarded the 2012 Certificate of Merit of the American Society of International Law. In 2017, I was awarded an advanced grant by the European Research Council for a project on “The Paths of International Law: Stability and Change in the International Legal Order”. I am also a member of the Council of the International Society for Public Law.