Diarmaid MacCulloch is Professor of the History of the Church at Oxford and a Fellow of St Cross College, Oxford. His Thomas Cranmer (1996) won the Whitbread Biography Award, the James Tait Black Prize and the Duff Cooper Prize; Reformation: Europe's House Divided (2003) won the Wolfson Prize for History and the British Academy Book Prize.

A History of Christianity: The First Three Thousand Years and the BBC television series based on it appeared in 2009; the book won the Cundill Prize, the world's largest history prize, in 2010.

His television series How God Made the English aired on BBC2 in March 2012. He is a Fellow of the British Academy and was knighted in the New Year's Honours List of 2012.