Diarmaid Ninian John MacCulloch, Kt, FBA, FSA, FRHistS (born 31 October 1951) is Professor of the History of the Church in the University of Oxford (since 1997) and Fellow (formerly Senior Tutor) of St Cross College, Oxford (since 1995).
Though ordained as a deacon in the Church of England, MacCulloch declined ordination to the priesthood because of the church's attitude to his homosexuality. In 2009 he encapsulated the evolution of his religious beliefs: "I was brought up in the presence of the Bible, and I remember with affection what it was like to hold a dogmatic position on the statements of Christian belief. I would now describe myself as a candid friend of Christianity."
Diarmaid MacCulloch was born in Kent, England. He attended Hillcroft Preparatory School and Stowmarket Grammar school in Suffolk. He subsequently studied history at Churchill College, Cambridge, where he obtained a BA degree in 1972 and an MA degree 1976. During that period, he was also organ scholar at the college. He then completed a Diploma in Archive Administration at Liverpool University in 1973 and then returned to Cambridge to complete in 1977 a PhD degree in Tudor history under the supervision of Sir Geoffrey Rudolph Elton, combining this with a position as Junior Research Fellow at Churchill College. MacCulloch was elected a Fellow of the Society of Antiquaries of London (1978), a Fellow of the Royal Historical Society (1982) and a Fellow of the British Academy (2001). He furthermore received a DD degree of the University of Oxford (2001) and in 2003 was awarded an honorary DLitt degree by the University of East Anglia. He co-edits the Journal of Ecclesiastical History.
MacCulloch joined the Gay Christian Movement in 1976, serving twice on its committee and briefly as honorary secretary. From 1978 until 1990, he was a tutor at Wesley College, Bristol and taught church history in the department of theology at the University of Bristol. He interrupted his teaching to study for the Oxford Diploma in Theology (awarded 1987) at Ripon College Cuddesdon. In 1987 he was ordained a deacon in the Church of England and from 1987 to 1988 he served as a non-stipendiary minister at All Saints' Clifton with St John's in the Diocese of Bristol. However, in response to a motion put before the General Synod in 1987 by the Revd Tony Higton regarding the sexuality of clergy, he declined ordination to the priesthood and ceased to minister at Clifton.
Regarding the conflict between his homosexuality and the Church of England and his own retreat from orthodoxy he said:
I was ordained Deacon. But, being a gay man, it was just impossible to proceed further, within the conditions of the Anglican set-up, because I was determined that I would make no bones about who I was; I was brought up to be truthful, and truth has always mattered to me. The Church couldn't cope and so we parted company. It was a miserable experience.
His book Reformation: Europe's House Divided 1490–1700 (2003) won the 2004 National Book Critics Circle Award and 2004 British Academy Book Prize, adding to his earlier success in carrying off the 1996 James Tait Black Memorial Prize for Thomas Cranmer: A Life. A History of Christianity: The First Three Thousand Years, was published in September 2009 with a related 6-part television series called A History of Christianity which first aired on BBC 4 in 2009 and then on BBC 2 and BBC 4 in 2010. The book won McGill University's Cundill Prize, a $75,000 prize, the largest such prize in Canada at the time.
MacCulloch was knighted in the 2012 New Year Honours for services to scholarship. While Debretts gives his formal style as "Prof Sir", MacCulloch has expressed the preference that he not be addressed in that manner, and the view that as an ordained deacon, this would also be formally incorrect. He sits on the European Advisory Board of Princeton University Press.
Awards and honours 
- 1996 James Tait Black Memorial Prize, Thomas Cranmer: A Life
- 2004 National Book Critics Circle Award, Reformation: Europe's House Divided 1490–1700
- 2004 British Academy Book Prize, Reformation: Europe's House Divided 1490–1700
- 2010 Hessell-Tiltman Prize, A History of Christianity
- 2010 Cundill Prize, A History of Christianity
- 2012 Knight Bachelor
- Suffolk and the Tudors (1986)
- The Later Reformation in England (1990)
- Henry VIII: Politics, Policy, and Piety (1995)
- Thomas Cranmer: A Life (1996)
- Tudor Church Militant: Edward VI and the Protestant Reformation (1999)
- republished as: The Boy King: Edward VI and the Protestant Reformation (2001)
- Reformation: Europe's House Divided 1490–1700 (2003)
- republished as The Reformation: A History (2005)
- A History of Christianity: The First Three Thousand Years. London, Allen Lane. (2009) ISBN 978-0-7139-9869-6
- Silence: A Christian History. London, Allen Lane. (2013)
- Debretts profile
- Daily Telegraph article
- BBC Press Office (2009): A History Of Christianity
- A History of Christianity, 11.
- "Search". The Globe and Mail (Toronto). 15 November 2010.
- How God Made the English at BBC Programmes
- The London Gazette: . 31 December 2011.
- "Prof Sir Diarmaid MacCulloch's Biography". Debrett's. Retrieved 11 April 2012.
- Tim Walker (9 January 2012). "Please, not Sir". Daily Telegraph (London). Retrieved 11 April 2012.
- Matt Pickles (5 January 2012). "Behind the shining armour". Arts at Oxford. University of Oxford. Retrieved 11 April 2012.
- Princeton University Press, European Advisory Board
- Crockford's Clerical Directory; 97th edition (London: Church House Publishing, 2001), p. 477.
- LGBT Religious Archives Network: profile: Diarmaid MacCulloch
- Website at St Cross College, Oxford
- Curriculum vitæ of Professor Diarmaid MacCulloch, provided by Saint Cross College, Oxford
- BBC Documentary A History Of Christianity