Diarmaid MacCulloch is Professor of the History of the Church at Oxford University. His Thomas Cranmer (1996) won the Whitbread Biography Prize, the James Tait Black Prize and the Duff Cooper Prize. He is the author most recently of Reformation: Europe's House Divided 1490 - 1700 (2004), which won the Wolfson Prize for History and the British Academy Prize. His six-part television history of Christianity airs on BBC television this autumn.