When Sir Denys Page died in July 1978, he left behind him the typescript of a substantial volume, marked with a pencilled note: ‘Ready for the Press, except that it would be the better for a critical eye.’

Our eyes are doubtless not as critical as they ought to be, but we have done what we could, in a field in which neither of us is a specialist, to perform such duties as seemed to us necessary. We have tacitly made numerous minor adjustments, but when in doubt we have preferred to incur the charge of doing too little to that of doing too much. On the rare occasions when we have intervened to make an alteration or addition of more substance to Sir Denys' exposition, we have apprised the reader by adding the initials of whichever of us was responsible. We have also compiled the Indices.

This book was already in the hands of the printer when we were fortunate enough to meet Dr P. A. Hansen, previously known to us only by his writings and as an authority mentioned in Sir Denys' Preface. We would like to acknowledge the generous help Dr Hansen has given us in improving this volume at proof stage.

Acknowledgements are also due to the anonymous Press reader, who pursued his investigations with an enthusiasm far beyond the call of duty.