Gilbert Márkus was a Dominican friar for 21 years, and ordained a priest in 1987. He studied theology at Blackfriars Oxford and at Edinburgh University (B.D., M.Th., S.T.L.) and taught and wrote on Liberation Theology for many years. On leaving the Dominicans in 2002, he taught and researched in medieval 'Celtic' history and theology at the universities of St Andrews, Edinburgh and Glasgow. He is currently finishing historical research in a four-year AHRC-funded research project on the monastery of Iona. His many books include The Radical Tradition: Saints in the Struggle for Justice and Peace (DLT, 1992).