At Durham, Professor Louth gave courses on the history and theology of the Christian Church. His research engages with the history of theology in the Greek tradition, especially after the fifth century, in the period of the Byzantine Empire (up to 1453), but also later, especially in the modern period, where his research interests also include Russian and Romanian (Orthodox) theology. His research is not purely historical, as he regards dialogue with the theological writers of the past as a resource for theological reflection today. Within this tradition, theology is not separated from prayer and spirituality.

His publications include Origins of the Christian Mystical Tradition: from Plato to Denys; Discerning the mystery: an essay on the nature of theology; and books on Dionysios the Areopagite, Maximos the Confessor, and John Damascene. He has also written on the tradition of desert spirituality in the Christian tradition, and a book in a series on the history of the Christian Church over the last two thousand years: Greek East and Latin West: the Church AD 681-1071. He has been editor of the journal Sobornost, and co-editor of the series Oxford Early Christian Studies. He has served as President of the Ecclesiastical History Society, was a member of the British Academy Council from 2011 to 2014, and he is now a fellow of the British Academy.

Professor Louth has been a Trustee of the Centre for Marian Studies for many years and his wise counsel has always been appreciated by the members of our charity. We are now delighted that such an eminent scholar has accepted our invitation to be an Honorary Fellow of the Centre for Marian Studies and we are very grateful for his ongoing support of our work.