Mark is Academic Dean, co-ordinating all the academic programmes with Durham and Oxford. He teaches Modern Church History and Theology. He is also Professor of the History of Modern Theology in the University of Oxford and lectures in sociology of religion. He is Canon Theologian of Truro Cathedral as well as Associate Priest in the Benefice of Garsington, Horspath and Cuddesdon. He was awarded a Doctor of Theology honoris causa from the University of Bonn in 2021.

Mark is currently Co-Chair of the Meissen Theological Conference. He also served on the history working group preparing the House of Bishops’ Teaching Document, Living in Love and Faith. He has written and edited books in many different areas of theology and church history. His most recent monographs are Theology at War and Peace: English Theology and Germany in the First World War (Routledge, 2017); Theology and Society in Three Cities: Berlin, Oxford and Chicago, 1800-1914 (Cambridge: James Clarke, 2014); The Fantasy of Reunion: Anglicans, Catholics, and Ecumenism, 1833-1880 (Oxford University Press, 2014). He has recently edited Reflections on Episcopacy in Theory and Practice (with Frank-Dieter Fischbach, Friederike Nüssel and Matthias Grebe (Evangelische Verlagsanstalt, 2022); Serbia and the Church of England: The First World War and a new Ecumenism (with Bogdan Lubardic) (Palgrave Macmillan, 2022); Changing the Church (with Vladimir Latinovic) (Palgrave Macmillan, 2020), Revisiting the Meissen-agreement after 30 years (edited with Matthias Grebe and Friedericke Nüssel) (Evangelische Verlagsanstalt, 2020); Costly Communion: Ecumenical Initiative and Sacramental Strife in the Anglican Communion (with Jeremy Bonner) (E.J. Brill, 2019), New Approaches in History and Theology to Same-Sex Love and Desire (with Dominic Janes) (Palgrave Macmillan, 2018), Hope in Ecumenical Future (Palgrave Macmillan, 2017), and The Oxford Handbook of Anglican Studies (with Martyn Percy and Sathi Clarke) (Oxford University Press, 2015). He is also author and editor of many other books including Anglicanism: A Very Short Introduction (Oxford University Press, 2006) and Anglican Theology (T & T Clark, 2012). He has also written a history of Christianity in Cuddesdon, God's Holy Hill (The Wychwood Press, 2004) and edited a book on the history of the College: Ambassadors of Christ (Ashgate, 2004).

Mark was brought up in South-east Essex and Berkshire and studied Politics and Philosophy, and then Theology at Trinity College, Oxford. He also spent a year in Munich during his doctoral studies. After his doctorate he was Stephenson Research Fellow at the University of Sheffield before he joined the staff at Cuddesdon in 1992. Mark trained on the Oxford Ministry Course and was ordained deacon in 1994 and priest in 1995. He is married to Linda and they have two grown-up sons. He likes travelling, cooking, good food, films, theatre, politics and Radio 3.