He describes himself as a "cradle Catholic" and specializes in 15th- to 17th-century religious history of Britain. He is also a former member of the Pontifical Historical Commission. His work has done much to overturn the popular image of late-medieval Catholicism in England as moribund, and instead presents it as a vibrant cultural force. On weekdays from 22 October to 2 November 2007, he presented the BBC Radio 4 series 10 Popes Who Shook the World - those popes featured were Peter, Leo I, Gregory I, Gregory VII, Innocent III, Paul III, Pius IX, Pius XII, John XXIII, and John Paul II.
Prizes and awards
- Hawthornden Prize for literature in 2002: The Voices of Morebath: Reformation and Rebellion in an English Village
- Longman-History Today Award for book of the year: The Stripping of the Altars: Traditional Religion in England 1400-1580
- Honorary fellowship from St Mary's College in 2003 (he later resigned from the position in protest at management decisions at the college made by its principal, Philip Esler)
Honorary Doctorates from the Universities of Durham, Hull, and King's College London, and from the Pontifical Institute for Medieval Studies, Toronto. Honorary Member of the Royal Irish Academy.
- Humanism, Reform and the Reformation: The Career of Bishop John Fisher (1989), with Brendan Bradshaw
- The Stripping of the Altars: Traditional Religion in England, c.1400 to c.1580 (1992)
- Saints and Sinners, a History of the Popes. Yale University Press. 1997. ISBN 0-300-07332-1.
- The Voices of Morebath: Reformation and Rebellion in an English Village (2001)
- Faith of Our Fathers: Reflections on Catholic Tradition (2004)
- Walking to Emmaus (2006)
- Marking the Hours: English People and Their Prayers, 1240-1570 (2007)
- Fires of Faith: Catholic England under Mary Tudor (2009)
- Ten Popes Who Shook the World (2011) ASIN B00680FXEY
- Saints, Sacrilege and Sedition: Religion and Conflict in the Tudor Reformations (2012) ISBN 1441181172
- "Confessions of a Cradle Catholic"
- Alphabetical list of all fellows, Magdalene College, Cambridge.
- Eamon Duffy profile
- Ten Popes Who Shook the World, BBC Radio 4