Professor Marc Weller

Professor Marc Weller is the Director of the Global Governance and Security Centre and Programme Director of the International Law Programme at Chatham House. 

Professor Weller holds the Chair of International Law and International Constitutional Studies in the University of Cambridge. His teaching focuses on public international law, including the use of force, dispute settlement, self-determination and peace-making.

In 2011/12 he served as a full-time senior mediation expert in the Department of Political Affairs of the United Nations Secretariat in New York, was senior legal advisor in the UN-led Vienna process of final status negotiations between Kosovo and Serbia, senior expert for the African Union in relation to the North-South Sudan pre-referendum negotiations, and served as senior advisor to UN Special Representatives for Syria (Kofi Annan, Lakhdar Brahimi and Staffan de Mistura) and to Jamal Benomar, former UN Under Secretary-General for Yemen. He is the co-editor of International Law and Peace Settlements, CUP 2021.

He joined Chatham House in October 2025. He is a Professor in the University of Cambridge and a former senior UN mediation expert.