In 1963 he delivered the annual James Ford lectures in British History at the University of Oxford on "William the Conqueror:The Norman Impact upon England" as documented in the Wikipedia article entitled Ford Lectures. The following year his book with the same title was published by Eyre Methuen Ltd.
A new edition was published by Yale University Press in 1999 as part of the Yale English Monarchs series with a new foreword by Frank Barlow. The back cover of the book states that Professor C Douglas was Professor of History at the University of Bristol and founding editor of the English Monarchs series and in the Preface reproduced from the original 1964 edition Professor Douglas alludes "specially to my friends in the University of Bristol" in his thanks to those who helped him in connexion with this work.
Works
William the Conqueror: The Norman Impact Upon England (May 1964)