Dietrich Bonhoeffer (1906-45) is one of the most influential Protestant theologians of the twentieth century. His death at the hands of the Nazis has made him a modern martyr and an icon of radical Christianity. Samuel Wells is Vicar of St Martin in the Fields, London, and is the author and editor of many acclaimed books including What Anglicans Believe, God's Companions (shortlisted for the Michael Ramsey Prize) and Power and Passion, the 2007 Archbishop of Canterbury's Lent Book. Previously he was Dean of Chapel and Research Professor of Christian Ethics at Duke University, North Carolina, and has worked closely with Stanley Hauerwas.