I completed my BA and PhD at the University of Cambridge, where I was subsequently a research fellow, and held a lectureship at the University of Sheffield from 1996. I have been Professor of Medieval History at Swansea University since 2007.
My research concerns the history of France and the British Isles in the Central Middle Ages (especially the Anglo-Norman realm, the Angevin Empire, and Capetian France), and medieval frontier societies. My earlier publications include The Norman Frontier in the Twelfth and Early Thirteenth Centuries (Cambridge: Cambridge University Press, 2004), and I edited The Central Middle Ages (Short Oxford History of Europe)(Oxford: Oxford University Press, 2006) and (with Naomi Standen) Frontiers in Question: Eurasian Borderlands 700-1700 (Basingstoke: Macmillan Press, 1999).
More recently, my research has concentrated upon the Anglo-Norman aristocracy after the collapse of the Anglo-Norman realm in 1204. Between 2016 and 2018 I held a Leverhulme Major Research Fellowship for the project ‘The Separation of England and France, 1204-1259’, which investigated the disintegration of the political and social ties that had been established between England and Northern France during the Anglo-Norman period. Alongside this research project I am also preparing a critical edition of the charters of the constables of Normandy in the 12th and 13th centuries. Some of my other recent publications have concerned the aristocracy of the Welsh March, and the participants in the Albigensian Crusade (1209-29). I have supervised doctoral students on a wide variety of topics relating to France and the British Isles between the 11th and early 14th centuries, including in joint supervision with French universities, and I would welcome applications from prospective research students wishing to work on this period.
I am a member and former director of MEMO, Swansea University’s Centre for Medieval and Early Modern Research, and a Fellow of the Society of Antiquaries (of London) and of the Royal Historical Society.