He is Professor of Ancient History at the University of Cantabria and has previously worked as a teacher at the Complutense University of Madrid and Salamanca and Murcia, and visiting professor at several Italian universities. He has devoted most of his research to the study of ancient Christian sources and the evolution of Christianity in the context of social, economic and ideological history of the Roman and Byzantine Empire. His publications include the monograph emperors, bishops, monks and women. Protagonists of early Christianity (1999) and collaboration in the History of Christianity I. The Ancient World (coordinated by Manuel Sotomayor and José Fernández Ubiña) (2006), both published works in this same Publisher. In 2002 he was awarded honorary doctorates by the University of Bologna and is currently President of the Spanish Society of Sciences of Religions (SECR).