Member and Past-President, International Mathematical Union, 2007-10.

Chair, IMU Committee on Electronic Information and Communication (CEIC).

Programme Committee, International Centre for Mathematical  Sciences, Edinburgh, 1991-.

Member, Board of Governors and Scientific and Academic Advisory Committee, Weizmann Institute, Rehovot, Israel, 1998-.

Council, Weizmann Institute Foundation, 2000-.

Conseil de Recherche et de l'Enseignement, Ecole Polytechnique, Palaiseau, 2001-.

Chair, Scientific Steering Committee, (and Member of Management Committee, National Advisory Board), Isaac Newton Institute, Cambridge, 2006-.

Science Steering Committee, National Institute for Environmental eScience, Cambridge, 2001-.

Peter Gruber Foundation Cosmology Prize Committee 2002-

International Council for Science, 2003-

Member, Engineering and Physical Sciences Research Council College.

Delegate, Oxford University Press 1998-.

Vice-Chairman, Mathematical Institute.

Chair, Research Committee of the Mathematical Institute.

Mathematical Institute Executive Committee.

Mathematical Institute Departmental Committee.

Mathematical Prizes Committee.

Mathematical Institute Building Committee.

Mathematical Institute Development Committee.

Mathematical, Physical and Life Sciences Divisional Board.

Halley Lectureship and Board of Trustees of the Johnson  Memorial Prizes.