A guide to the most elusive source of international law
This is a hybrid event
Customary international law is a crucial source of international law because once it is identified, it is binding on all States. But determining whether an applicable rule of customary international law exists is not always simple or straightforward.

Moderated by the School’s Professor of International Law Philippa Webb, Sir Michael Wood and Dr Sender, the authors of Identification of Customary International Law, will share guidance and insights on how to determine the existence and content of rules of customary international law.

They will reflect on the methodology and examine practical questions concerning the process and evidence involved. Professors Çalı and Akande will serve as discussants. There will be plenty of time for questions, including on the challenges of providing advice in a shifting legal landscape.

The book launch is followed by a drinks reception.

The event is jointly hosted by the Blavatnik School of Government, the Bonavero Institute and the Faculty of Law, University of Oxford.
Date: 3 March 2025, 17:00
Venue: Blavatnik School of Government, Radcliffe Observatory Quarter OX2 6GG
Venue Details: In person and online
Speaker: Various Speakers
Organising department: Blavatnik School of Government
Organiser: Blavatnik School of Government (University of Oxford)
Organiser contact email address: events@bsg.ox.ac.uk
Booking required?: Required
Booking url: https://www.bsg.ox.ac.uk/events/guide-most-elusive-source-international-law
Cost: This event is free - please register at the above link
Audience: Public
Editor: Anna Ulshofer