Antonios is Associate Professor of Public International Law at the University of Oxford; a Law Fellow of St Anne’s College, Oxford; and the Secretary-General of the International Law Association. He is also a qualified Greek lawyer (admitted 2004).

Antonios specialises in public international law; his practice includes advice and advocacy in relation to traditional inter-State disputes (including before the International Court of Justice), investment protection disputes, international human rights law, issues of sovereign immunity, State succession, State responsibility, the law of treaties, and the law of the sea.

Antonios has acted as counsel, advisor, or assistant to counsel, and has provided expert opinions, in a number of cases before international and domestic courts and tribunals, including the International Court of Justice, EU courts, the European Court of Human Rights, ad hoc and ICSID arbitral tribunals, and the High Court of England and Wales. Among his more notable cases as counsel are: in the ICJ, the /Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 /(for Cyprus), and in ICSID tribunals, ICSID Case No. ARB/14/2 (for Sudan).

Antonios has published widely on questions of international law. His books include:

  • Disobeying the Security Council /(OUP 2011, re-issued in paperback with a new introduction 2013)
  • The Settlement of International Disputes (Hart 2012, co-edited with CJ Tams)
  • The UN Convention on Jurisdictional Immunities of States and their Property (OUP 2013, edited by R O’Keefe and CJ Tams, ass’t ed)
  • and the Research Handbook on the Law of Treaties (Elgar 2014, co-edited with CJ Tams and A Zimmermann, and re-issued in paperback 2016).

He has also published in the fields of the law of the sea, international investment law, and others. Antonios has held visiting appointments in France (Paris X), Israel (IDC Herzliya), and China (China University of Political Science and Law).

Antonios is fluent in German and Greek, and has a working knowledge of French.