I was Warden of Keble College from 1994-2010, and before that Professor of Late Antique and Byzantine History at King's College London where I was also the first Director of the Centre for Hellenic Studies. I held a Leverhulme Emeritus Fellowship in the Faculty of Theology 2011-13, and am chair of the Oxford Centre for Byzantine Research. I have been President of CBRL (Council for British Research in the Levant) and FIEC (Fédération internationale des associations d'études classiques) and am currently President of the Society for the Promotion of Byzantine Studies.