He is Professor of Ancient History and director of the Institute of History at the University of Potsdam; previously was a professor at Eichstatt, Heidelberg and Erfurt. He has been a visiting lecturer at the College de France and at the University of Pretoria, among other institutions. He is a corresponding member of the Real Academia de la Historia (Madrid) and Doctor Honoris Causa by the Universitat Jaume I of Castellón. As a reward for his research career, he has recently obtained the "Chair of Excellence" of the Carlos III University of Madrid. Directs European historical research group "Potestas".