In William the Conqueror, Professor Douglas analyzes the causes and the true character of the Norman impact upon England in the eleventh century. The work is both a study of Anglo-Norman history and a biography of a man whose personal career was spectacular, and as reviewers have remarked, it is distinguished by a wealth of scholarship linked to a lucid and agreeable style.

"Douglas' William the Conqueror possesses the real and elusive quality of greatness. . . . Its originality will surely become the orthodoxy of the next generation."—Speculum

"This book, with its appendices, its pedigrees and its bibliography, is a monument of careful scholarship and fine printing. Its author would probably hope that it may be adjudged his masterpiece, and it is certain that it will be for many years the ruling authority on its subject. Much of it is detailed history of tightly woven discussion, but it is notably well written..."—Times Literary Supplement

"Professor Douglas brings to his study of the Conqueror a far-ranging knowledge of medieval life and institutions, the outcome of a lifetime's devoted and discriminating familiarity with medieval sources. He has also, unlike earlier English biographers of William, made full use of valuable French scholarship in dealing with the development of the Duchy of Normandy. His book is thus a truly European study of this remarkable man and his epoch. He illuminates in his pages the growth of ideas and institutions which, however remote they may seem from today, have exerted a powerful influence on the political growth of the English-speaking peoples. This outstanding work of scholarship is the first book in a series to be devoted to English rulers. It could not have a more impressive beginning."—C.V. Wedgewood, in Book Week