02/09/2025

Payam Akhavan becomes a member of Twenty Essex

We are pleased to announce that the leading public international law practitioner Professor Payam Akhavan has this week joined Twenty Essex in London as a barrister.

Payam is an experienced independent lawyer with broad international expertise. Over three and a half decades, he has acted in every major international forum, including the International Court of Justice, International Tribunal for the Law of the Sea, International Criminal Court and tribunals constituted under the Permanent Court of Arbitration, as well as the European Court of Human Rights, the Inter-American Court of Human Rights, and the Supreme Courts of the United States and Canada. He has stood as counsel and advocate in more than 30 sovereign disputes, representing numerous states, including as counsel to the Commission of Small Island States on Climate Change and International Law. Payam has also represented heads of state and governments, working across the full spectrum of international law.

A respected academic, Payam is Senior Fellow and inaugural Chair in Human Rights at Massey College, University of Toronto. He was previously a Full Professor at McGill University Faculty of Law (Montreal), and Distinguished Visitor at the University of Toronto Faculty of Law, with other appointments at Sciences Po and Université Paris Nanterre, Oxford University, European University Institute in Florence and Yale Law School. He has published extensively on human rights and international criminal law, and is on the editorial review board of Human Rights Quarterly.

Payam is an Associate Member of the Institut de droit international (IDI), former Member of the Permanent Court of Arbitration, and former Special Advisor to the Prosecutor of the International Criminal Court. He was the first Legal Advisor to the Prosecutor’s Office of the International Criminal Tribunal for the former Yugoslavia at The Hague, and has served with the United Nations in investigations relating to conflict zones and allegations of genocide around the world.

In 2021, Payam was appointed to the Order of Ontario, the province’s highest civilian honour, and elected a Fellow of the Royal Society of Canada.

Twenty Essex has an exceptional and longstanding history in public international law, including past members such as Arnold (Lord) McNair, Sir Hersch Lauterpacht, Sir Arthur Watts and Professor David Caron. Current members include Sir Michael Wood KC, Sir Daniel Bethlehem KC and Lord Verdirame KC, as well as senior international arbitrators and judges: former ICJ President Judge Joan Donoghue joined Twenty Essex in January 2025, further bolstering a group of arbitrators that also includes former ICJ judge ad-hoc, The Hon Charles N Brower.

In a joint message, Philip Edey KC and Charles Kimmins KC, co-heads of chambers, commented:

“We are very pleased to welcome Professor Akhavan to Twenty Essex. Payam is a renowned advocate and international lawyer with a longstanding independent practice, and we are delighted that he has chosen Twenty Essex as a new base from which to continue and expand his career. Public international law is at once a proud strength of chambers in its own right, and an increasingly essential complement to the work of an international commercial disputes practice, in light of the varied, complex and interwoven challenges and ramifications that arise in the course of litigation and arbitration on the global stage. It is exciting that fellow members and co-counsel will have the opportunity to draw on Payam’s expertise and experience in these areas, and we wish him every success with this new chapter in an already distinguished career.”

Payam Akhavan added:

“I am honoured to join Twenty Essex, with its exceptional legacy of eminent international jurists. I have had the pleasure of collaborating with several outstanding barristers at the chambers over the years. I look forward to strengthening those ties at a time of significant global change and unprecedented recourse to international courts and tribunals. Navigating this complex landscape requires brilliant minds and sound judgment, which are abundant at Twenty Essex.”

In addition to his call to the bar of England and Wales, Payam has been called in New York (2002) and Ontario (2012). His barrister’s practice will be managed via Twenty Essex’s London-based team.

Contact the practice management team to find out more.