It is both a duty and a pleasure to thank the various people who have given generously of their time in reading and commenting on my various drafts. Henry Chadwick, Michael Lapidge, Dáibhí Ó Cróiníh, Elizabeth Jeffreys, Andy Orchard, Winifred Temple, Neil Wright, David Dumville and Richard Sharpe have all been extremely helpful. Lesley Abrams and Simon Keynes both answered queries about charters, for which I am most grateful. Michael Lapidge collated the Vatican manuscript on my behalf, and also allowed me to use his Biblical Commentaries pre-publication. I owe a particular debt to David Dumville, for his generous loan of his complete set of photographs of the Vatican MS of the Laterculus, which formed the basis of my edition. I would also like to thank Carmela Vircillo Franklin for giving me xeroxes of her edition and commentary on the Passio S. Anastasii, and Elizabeth Jeffreys for sending me most of the Studies volume months before it came out. Peter Davidson performed the traditional duties of an academic spouse by checking references in the final stages. Earlier versions of the main arguments in the Introduction were presented as papers to the Cambridge Classics Faculty seminar on the transmission of Latin texts in the Middle Ages, and the seminar which was held in the Department of Anglo-Saxon, Norse and Celtic to mark the 1300th anniversary of the death of Archbishop Theodore in 1990. I am indebted to participants at both these occasions for illuminating comments and helpful information.