• Professor of Early Christian History and Iconography, King’s College, London
• Affiliated Lecturer, University of Cambridge, Faculty of Divinity (2008-2010)
• Acting Dean, St Edmund’s College, Cambridge (2012-2013)
• Associate Professor in History, James Cook University of North Queensland (1980-1995)
• Professore Invitato, Institutum Patristicum Augustinianum, Pontificia Universitas Laterenses Rome 2011-2012)
• Visiting Professor and Senior Research Fellow BARDA PROJECT, (with Prof. Markus Vinzent) Early Christian Iconography, Department of Theology and Religious Studies, King’s College London (2011-2017)

Research interests and PhD supervision

My field in Early Christian History, exploring the interface between Christianity and Classical Culture is particularly seen in:

1. The development of Church Order
2. The phenomenon of cultural transformation in the medium of early Christian and ambiguously Pagan forms of art
3. The attempt of Constantius II to develop a political theology of Christian imperial unity

My work considers epigraphy and iconography an essential part of the reconstruction of early Christian history without which any historical account will lack a viable interpretation of events.

Teaching

Christianity and Classical Culture

Expertise and public engagement

Joint editor with Markus Vinzent of  Studia Patristica  and is a member of the editorial board of  Vetera Christianorum.

I was responsible for giving a rational theological form to proposals for the creation of cultural bishops for the Anglican Aboriginal and Islander communities of Australia.

Selected publications

• Hippolytus and the Roman Church in the Third Century: Communities in Tension before the Emergence of a Monarch-Bishop (Supplements to Vigiliae Christianae 31 Leiden: E.J. Brill 1995).
• Ignatius of Antioch and the Second Sophistic, (Studien und Texte zu Antike und Christentum 36; Tübingen: Mohr Siebeck 2006).
• A Political History of Early Christianity, (London: Clarke-Continuum 2009).
• Cyprian and Roman Carthage (Cambridge: University Press 2010)
• ‘Has the Vita Abercii mislead epigraphists in the reconstruction of the inscription?’ in The First Urban Churches Vol. 5:. Colossae, Hierapolis, and Laodicea, Eds. James Harrison and Larry Welborn (Writings from the Greco-Roman World. Supplement series, 16; Atlanta: SBL Press, 2019).