Robert Somerville is a specialist in pre-modern Western Church history and canon law, especially of the eleventh through the thirteenth centuries, and is the author of many books and articles on Church history from the fourth through the sixteenth centuries. His book on Pope Urban II's Council of Piacenza (1095) forms a kind of trilogy with his earlier volumes on Urban's Council of Clermont (1095), and the Council of Melfi (1089) and the Collectio Britannica. Prof. Somerville is a fellow and corresponding fellow of several academies and learned societies in the United States and in Europe, including the Medieval Academy of America and the Bayerische Akademie der Wissenschaften. In addition to Columbia University he has taught at the University of Pennsylvania, and has been a visiting professor at the University of California, Berkeley, and at New York University, and also has lectured at conferences and universities in North America and in Europe.