I would like to acknowledge my thanks to the librarians of the British Library, London; the Bodleian Library, Oxford; and the Forschungs- und Landesbibliothek, Gotha; and the Master and Fellows of Corpus Christi College, Cambridge, who made the relevant manuscripts available for consultation; provided copies of the the pages containing the texts edited in the appendices; and granted permission to publish those texts. I am grateful to the Rev. David Wiseman for granting permission to view and photograph the St Helena windows at the Parish Church of St Michael and All Angels, Ashton-under-Lyne, and to Karin Olsen and Jennifer Neville for accompanying me on a memorable journey there.

The consultation of manuscripts and other materials was made possible by the financial support of the Australian Research Council and the University of Sydney.

It is a pleasure to thank the many people who have discussed this project with me and offered valuable assistance: to Helen Fulton who generously made translations from Welsh for me, and to my other colleagues at Sydney, Margaret Clunies Ross and Diane Speed, for their advice and assistance on various sections of this project. I gratefully acknowledge help and advice received from: Robert Bartlett, Helen Cooper, Jan Willem Drijvers, C.E.V. Nixon, George Rigg, Susan Rosser, John O. Ward, Jocelyn Wogan-Browne, Alex Woolf, and the anonymous reader for Boydell & Brewer. I am also happy to express my appreciation for the research assistance provided by Don Gillett in London and Carol Percy in Toronto, for proof-reading done by Craig Ronalds, and technical aid given by Beth Lewis in Sydney.