Derek Pearsall is the Gurney Professor of English at Harvard University and was Professor and Co-Director of the Centre for Medieval Studies at the University of York, 1965-85. His numerous publications include "John Lydgate" (1970), "Old English and Middle English Poetry" (1977), "The Canterbury Tales: A Critical Study" (1985), "An Annotated Critical Bibliography of Langland" (1990) and "The Life of Geoffrey Chaucer" (1992).