Diarmaid MacCulloch is an English academic and historian who specializes in ecclesiastical history and the history of Christianity. Born in Kent in 1951, he has spent his career at the University of Oxford, where he held the position of Professor of the History of the Church from 1997 to 2019. Since 1995, MacCulloch has been a fellow of St Cross College, Oxford, where he previously served as senior tutor. Following his professorship, he took on the role of senior research fellow and archivist at Campion Hall, Oxford, a position he has held since 2020.